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i2 



WORKS OF I. McKIM CHASE 



PUBLISHED BY 



JOHN WILEY & SONS. 



Screw Propellers and Marine Propulsion. 

8vo, X -f- 230 pages, 31 full-page plates. Cloth, $3.00. 

The Art of Pattern-making. 

A Comprehensive Treatise. Numerous Examples of 
all kinds of Pattern Work for Green-sand, Dry-sand, 
and Loam Moulding. Pattern Work for Marine En- 
gines and Screw Propellers. Also Useful Inforii a- 
tion and Rules for the Practical Use of Pattern-makers 
and Others. lamo, vi -|- 254 pages, 215 figures. 
Cloth, I2 50. 



THE ART 

OF 

PATTERN-MAKING. 

A COMPREHENSIVE TREATISE, 



NUMEROUS EXAMPLES OF ALL KINDS OF PATTERN WORK 
FOR GREEN-SAND, DRY-SAND, AND LOAM MOULDING. 
PATTERN WORK FOR MARINE ENGINES AND 
SCREW PROPELLERS. ALSO USEFUL INFOR- 
MATION AND RULES FOR THE PRACTI- 
CAL USE OF PATTERN-MAKERS 
AND OTHERS. 



BY 

I. McKIM CHASE, M.E. 






FIRST EDITION, 
FIRST THOUSAND. 



NEW YORK: 

JOHN Wn.EY & SONS. 

London : CHAPMAN & HALL, Limited. 

1903- 



THE LfBRARYOF 
CONGRESS. 

Two Copies Received 

JUL 28 '00? 

copyright Entry 
kSsO ^ XXo No. 

ic U- ^ o 

COPY A. 



T 






Copyright, 1903, 

BY 

JOHN WILEY & SONS. 



fcCC , c t 



ROBERT DRUMMOND, PRINTER, NEW YORK. 



3 




f/i^l 



PREFACE. 



The author's extensive experience in connection 
with pattern-making in nearly all of its variations 
impressed him with the belief that great benefit 
would be derived by many members of the craft by 
acquiring a more general knowledge of the busi- 
ness. No individual can have had the experience 
of many. The acquisition, then, of the knowledge 
of others must be gained through lectures or litera- 
ture. The literature pertaining to pattern-making 
is by no means as extensive as the importance of the 
business warrants. There are many pattern-makers 
competent to treat the subject in a satisfactory 
manner, but have been deterred by the amount 
of time and labor necessary to do the subject 
justice. 

The subjects chosen for illustration herein are 
chiefly those with which the author has had per- 
sonal experience and were originally written for 
publication in "Machinery." He also records the 
experience of others in pattern -making ; these ex- 
amples have been selected chiefly from the corre- 
spondence of the ''American Machinist." He has 

iii 



IV PREFACE. 

embodied whatever in his opinion would be of interest 
to the pattern-making fraternity. 

Providing for the interior of castings, or core-box 
work, is correctly regarded as the most intricate and 
important part of pattern-making. Amongst the 
subjects several excellent examples of core-box 
work will be found. 

Screw propellers are a special feature, and the 
examples given are thoroughly elucidated. 

The author has always entertained a deep interest 
in pattern -making owing to its intricacy, the skill and 
intelligence required for its execution. In present- 
ing this volume to its readers he hopes and believes it 
will be found a useful and desirable acquisition to 
the literature of pattern-making. 



CONTENTS. 



PAGE 

I. Introduction ^ 

II. Equipment of a Modern Pattern-shop 13 

III. The Management of a Modern Pattern-shop 24 

IV, Pattern Work for Moulding in Loam 34 

V. Pattern Work for a Cylinder 39 

VI. Pattern Work for an Elbow 44 

VII. Pattern Work for Steam-cylinder of Marine Engine 49 

VIII. Pattern Work for a Pedestal 5^ 

IX. Pattern Work for Screw Propellers when Swept Up in 

Loam « ^i 

X. Pattern Work for Rifle-projectiles 74 

XI. Pattern for Launch-engine 7^ 

XII. Patterns of Deck-lug for Dry-sand Moulding 83 

XIII. Pattern Work for Water-collar 88 

XIV. Pattern Work for High- pressure Cylinder for Marine 

Engine 93 

XV. Pattern for a Gun-mount Pedestal 100 

XVI. Pattern Work for Screw Propeller Cast Entire 104 

XVII. Method of Making a Pattern for a Screw Propeller with 

Separable Blades "2 

XVni. Construction of Small Screw Propellers 123 

XIX. Pattern Work for Moulding a Large Belt-pulley or Fly- 
wheel \ ^32 

XX. Pattern for an Oblique Chute 137 

XXI. Patterns with Branches 1 43 

XXII. Teeth of Gear-wheel Patterns • • I55 

XXIII. Belt-pulleys and Fly-wheels - 160 

XXIV. Standard Patterns ^^ 

V 



VI 



CONTENTS. 



PAGE 

XXV. Glue and its Use i68 

XXVI. Loose Pieces 170 

XXVII. Wood Lagging for an Elbow 171 

XXVIII. The Lathe and Lathe-work 175 

XXIX. How to Make a Wooden Face-plate 182 

XXX. Marking, Recording, and Storing Patterns 184 

XXXI. Sectignal Lining in Mechanical Drawings 190 

XXXII. Practical Geometry 192 

XXXIII. Some Useful Rules for the Shop 200 

XXXIV. Handy Tools for Pattern-makers 212 

XXXV. Method of Making Special Shrinkage Rules 216 

XXXVI. A Handy Straight edge for Marking 218 

XXXVII. Filing Hand-saws 219 

XXXVIII. Wax Fillets 222 

XXXIX. Inserting Wood-screws into End Grains of Wood 224 

XL. Board Measure 226 

XLI. To Compute Volume of Squared Timber 227 

XLII. Timber Measure 228 

XLIII. Strength and Weight of Woods 229 

XLIV. Miscellaneous Tables, etc 230 

XLV. Standard Wood-screws 234 

XLVI. How to Approximate the Weight of an Iron Casting 

from its Observation 236 

XLVII. Prismoidal Formula 241 

XLVIII. To Compute the Area of a Figure Bounded by a Curve . 245 

XLIX. Weights and Measures 248 



THE ART OF PATTERN-MAKING. 



I. 

INTRODUCTION. 

The art of pattern-making comprises the model- 
ing of objects that are intended to be cast of metals. 
Its origin is contemporaneous with that of the cast- 
ing of bronze, and, like that of the latter, the period 
of its inception is lost in the oblivion of remote 
ages. 

The first patterns were probably made of clay or 
of similar material, and were models of those rude 
bronze castings that have been found in ancient 
ruins. At a later period wax was employed for 
patterns which represented the more artistic bronze 
articles. In both these methods the models were 
usually destroyed in the process of moulding, and 
their consequent disappearance, in conjunction with 
the then existent limited knowledge of bronze found- 
ing, made the castings rare and valuable. 

In the ancient wax process the modeling was 
done directly in the wax. When the object was 
large a core representing the interior form of the 



2 THE ART OF PATTERN-MAKING. 

object was made of the same materials that formed 
the mould. Over this the wax was modeled and 
the mould was built around the model or pattern 
thus formed. In building the mould, inlets or gates 
through which the metal entered, and vents through 
which the gases escaped from the mould, were pro- 
vided; these were also represented in wax. When 
the mould was heated in the process of baking, the 
wax melted and escaped through outlets provided 
for the purpose during the construction of the mould. 

Wax is still used for patterns, although chiefly 
for ornamental work. In the modem process the 
modeling is done in clay, and a plaster mould made 
of the object thus modeled. The wax model is 
then produced by filling the plaster mould with 
molten wax. Plaster patterns are also used to a 
large extent in ornamental work. The process of 
producing them is similar to that of making wax 
patterns. 

For many kinds of patterns plaster is a convenient 
material. It will readily take impressions with 
fidelity, its durability is such that it will withstand 
repeated use, and it is sufficiently cohesive to allow 
of a pattern being made in sections for convenience 
in moulding. 

As the various arts requiring castings advanced 
and demanded larger and more complicated cast- 
ings, the art of founding progressed with it. To 
meet this created demand it became necessary to 
produce larger and more complicated as well as more 
durable patterns. 



INTRODUCTION. 3 

Wood, then, of all materials, has been found to 
possess the qualities which are requisite in the con- 
struction of large and intricate patterns at moderate 
expense. Of the various kinds of wood suitable for 
pattern work, clear, dry white pine stands pre- 
eminent. Its abundance and cheapness, the ease 
with which it can be worked, combined with its 
constancy in retaining its form, has induced its 
employment for pattern work to a greater extent 
than all other materials combined. The kind of 
pine that grows in the neighborhood of the Great 
Lakes is the best. It is better without knots or 
sap, although a small knot or a little sap occasion- 
ally is not objectionable, especially for large pat- 
terns, provided the wood is thoroughly seasoned and 
dry, for this latter quality is of the first importance. 

The shrinkage of white pine across the grain is 
well understood. It has been asserted that it will 
also shrink with the grain lengthwise, and under 
certain conditions this is possible to a small extent 
when the wood is of curly or cross-grained nature. 
A case of apparent shrinkage in length of white 
pine was related to the writer by a reliable person. 
In making a pattern he joined together two pieces 
of white pine and then planed off their ends, thus 
insuring their being of the same length. Subse- 
quently, after the pattern had been used for mould- 
ing and had been stored in the pattern loft for some 
time, it was noticed that the two pieces were of 
imequal lengths. From the nature of the construc- 
tion of the pattern and the position of the two pieces 



4 THE ART OF PATTERN-MAKING. 

in it, the opinion was formed that the shorter piece 
had shrunk in length. The resistance that soft, 
white pine offers to compression is not very great. 
If a piece of this wood, of cross-section small in 
comparison to its length, is left standing on end a 
sufficient space of time, it is possible for it to de- 
crease in length owing to its small power of withstand- 
ing compression, and thus create the belief that 
shrinkage was the cause of the change. For all 
practical purposes it may be said that soft, straight- 
grained white pine will not change its length by 
shrinkage. 

When patterns are to be subjected to rough 
usage, or are to be used for many castings, harder 
woods, such as baywood, cherry, ash, maple, etc., 
are selected. The first-named of these possesses 
some of the qualities of white pine, in that it is 
easily worked and will hold its shape well; but it 
is the most expensive of the woods used. Of late 
years redwood has been largely employed in mak- 
ing patterns, but, although somewhat cheaper, it 
does not work as freely as white pine. Except for 
large and plain patterns, where the cost of material 
amounts to a large proportion of the entire expense 
of construction, the use of redwood for pattern 
work is of doubtful economy. 

Metal patterns are also largely employed, but of 
course the original must have been made of wood 
or other material, and the metal pattern produced 
by process of founding. 

Green-sand moulding is practiced to a greater 



INTRODUCTION. 5 

extent than other methods, because it is the cheap- 
est for producing castings, especially for small work 
that is to be much duplicated. In .this the mould- 
ing is done in a suitable sand, moistened sufficiently 
to make it adhere together. Patterns for green- 
sand moulding are models of the object to be cast, 
and are made in such a manner that they may be 
readily withdrawn from the sand without mutilating 
the mould. To enable this to be accomplished the 
pattern is made in two or more sections, as the case 
necessitates, and so joined together as to allow the 
different parts to be withdrawn separately and in a 
manner depending on the form and position of the 
part. Core-prints are provided where necessary 
to locate and support the cores. Cores are bodies 
of prepared sand, baked. Their exterior form cor- 
responds to an interior part of a casting, or to under- 
cuts on its exterior that will prevent a model of it 
being withdrawn from the sand. In such a case the 
pattern is provided with core-prints which abolish 
the imdercuts and leave impressions into which 
cores are inserted to supply the part or parts of 
the mould made vacant by the core-prints. 

Dry-sand moulding is next in importance. In 
this method the moulding is done in sand mixed 
with raaterials that will cause it, after being baked 
in an oven, to adhere firmly together and withstand 
greater pressure without distortion than with green 
sand. Another advantage the dry-sand method 
possesses is that the mould may be "cheeked," as 
foundrymen say; that is, it may be divided into 



6 THE yiRT OF PATTERN-MAKING. 

a number of parts and those parts lifted away to 
relieve undercuts and similar places in the patterns. 
Statuary is moulded in this manner. 

Patterns for dry-sand moulding are constructed 
and finished in a similar manner to those for green 
sand, except that they can often be made with 
fewer pieces when the mould is to be " cheeked ' ' 
and drawbacks employed. 

Loam moulding is used for the larger and heavier 
castings. In this method the moulding is not done 
in a flask, as in the case of the two previously de- 
scribed methods, but is built up of brickwork, 
strengthened by rods and plates where necessary. 
The moulding material is a mixture of sand and 
other materials of about the consistency of mortar. 
It is worked into the mould between the pattern 
and brickwork. By this method the mould can 
be made into any number of necessary sections, 
which can be disjointed, thus relieving the pattern 
and allowing its withdrawal. When the sections 
are assembled in a pit and clamped together with 
sand firmly rammed around the mould the latter is 
prepared for the metal. 

In constructing a pattern to be moulded in loam 
it is advisable to use wood sparingly, and where it 
is used provision should be made for its swelling, 
which it will do by absorbing moisture from the 
loam. A strike or sweep used in loam moulding 
is a flat piece of board with the edge so shaped as 
to conform to the profile of a part of the desired 
casting by revolving it on a spindle or moving it 



INTRODUCTION. 7 

along guides, as the case requires. The required 
part of the mould can be formed without necessitat- 
ing the pattern being worked out for it. A pattern 
to be moulded in loam is often but a skeleton of 
woodwork, some parts of it representing corre- 
sponding parts of the intended casting and other 
parts forming guides for sweeps. For instance, the 
mould for a plain cylinder may be formed alto- 
gether with sweeps by securing them to a spindle 
and revolving them while building up the mould. 

Wooden patterns are usually finished with a 
coating of shellac dissolved in alcohol. This method 
is quick, furnishing a smooth surface, and provides 
protection against dampness when the pattern does 
not remain in the mould very long, as generally is 
the case with green-sand moulding. But when the 
pattern reraains in the mould for a length of time, 
especially in a loam mould, which is very wet, 
shellac does not afford a very good protection against 
the absorption of moisture by the pattern, and 
swelling is then the result. Painting the pattern is 
the alternative in this case, but it is seldom prac- 
ticed in this country, in consequence of its incon- 
venience. Thoroughly oiling the pattern previously 
to its being placed in a loam mould is the usual 
practice. 

All metals in passing from the liquid to the solid 
state suffer expansion when in the plastic condi- 
tion. It is this feature in the transition that en- 
ables metals to take and retain the impressions of 
moulds with such fidelity. In cooling from the 



8 THE ART OF PATTERN-MAKING. 

plastic condition to the solid state metals contract; 
the amount of this contraction to normal tempera- 
ture will vary for the various kinds of metals. 
Patterns have therefore to be made larger than the 
intended casting by this amount, and here occurs the 
necessity on the part of the pattern-maker for the 
use of discreet judgment based upon extended 
experience in order to obtain the best possible 
results, because different kinds of varying mixtures 
of iron as well as that of alloys will contract with 
varying amounts. Moreover, the varying propor- 
tions of castings when made of the same material 
will vary in their amount of contraction. Thus an 
extended and plain casting will contract differently 
from one of more compact form, though both may 
be of equal weight and cast at the same time and of 
the same material. It is necessary also to make 
an allowance for the parts of a casting that are to 
be finished, taking into consideration the liability 
of imperfection in the form of the casting. 

All woods contain moisture to some extent. Wood 
kept for several years in a dry place will contain 
15 or 20 per cent, of water. Wood that has been 
thoroughly kiln-dried will, when exposed to the air 
under ordinary circumstances, absorb 5 per cent, 
of moisture in the first three days, and will continue 
to absorb until it approximates 15 per cent, of 
water. Wood, however dry, is subject to change; 
it will swell or shrink according to the humidity 
of the atmosphere or the hygrometric conditions 
under which it is placed. These circumstances 



INTRODUCTION. 9 

must be taken into consideration when a pattern is 
about to be constructed, and the material so manipu- 
lated that its swelling and shrinking will counteract 
each other in order that the pattern may retain its 
form and dimensions as nearly as possible. 

There is another peculiarity of wood — its ten- 
dency to warp in one direction, the cause of which 
needs to be considered when a structure is to be built 
up with pieces of wood of various shapes and dimen- 
sions. 

When a tree is sawn across it is observed appar- 
ently to be made up of a number of annular rings. 
One ring is reckoned for each year in the age of 
the tree. These rings are composed of numerous 
minute tubes known as capillary tubes. The sap 
which gives life and growth to the tree is absorbed 
by its roots from the soil through which they run. 
This sap is conveyed through the capillary tubes 
or veins of the tree by a mysterious force known 
as capillary attraction. When the capillary tubes 
are deprived of moisture they contract in diameter 
and consequently the system which they compose 
becomes smaller. 

Fig. I illustrates a section of a tree with the 
capillary tubes somewhat exaggerated. If such a 
piece is cut at a season of the year when the tubes 
contain sap, it will split in the course of drying, as 
shown by Fig. 2, because the outside tubes dry out 
first and in shrinking the tenacity of the wood is not 
sufficient to overcome the resistance to compression 
offered by the wood within, which has not shrunk 



lo 



THE ART OF PATTERN-MAKINC. 



SO much, and consequently as the shrinkage occurs 
with great force the outer wood is pulled apart. To 
prevent this tendency to split, a hole is often bored 
through the center with the grain; this enables the 





Fig. 1. 



Fig. 



2. 



wood to dry and shrink from the inside as well as 
from the periphery. Fig. 3 shows the section cut 
with the grain into three parts, and Fig. 4 shows it 
cut into six parts ; they also show the direction in 





Fig. 



Fig. 4. 



which the shrinkage and warping occur. A knowl- 
edge of this tendency of wood to shrink and warp in 



INTRODUCTION. ii 

drying is important to possess, and a proper regard 
for it in joining woodwork will avoid many difficul- 
ties. 

Pattern-making is of infinite variety, and the 
pattern-maker is never done learning. New forms 
and devices are continually appearing ; these necessi- 
tate constant study and scheming on the part of 
the pattem-rriaker to meet the new conditions. An 
extended range of thought, skill, and experience is 
necessary for efficient pattern-making. A model 
of an object is not necessarily a pattern, because it 
may be made in such a manner that it will be im- 
practicable to mould it. 

To become an expert pattern-maker necessitates 
talents superior to those required for any of the 
branches of the machine business except designing. 
The pattern-maker should possess the qualifications 
of a moulder and also a draftsman, and must be able 
to read any mechanical drawing readily and conceive 
the form and intention of the object illustrated by the 
draftsman, and comprehend its details in the mi- 
nutest degree. He must be able to determine how 
and in what manner the object is to be moulded be- 
fore he can intelligently begin the construction of 
the pattern, and avoid the errors likely to occur by 
his inability to do so. Expert pattern-makers are 
classed with the best general mechanics. 

It is a mistaken opinion of some persons that any 
mechanic working in the trades where the chief 
material used is wood can work at pattern-making. 
The pattern-maker is trained to the greatest refine- 



12 THE ART OF PATTERN-MAKING, 

ment in the art of working wood. There are few 
employments which require greater speciaHzed 
knowledge of rather a wide range than that of 
pattern-making. 

Good carpenters and cabinet-makers can become 
pattern-makers after the necessary training, their 
degree of success as pattern-makers depending in a 
great measure on how great an impression the habits 
acquired in their respective trades have made upon 
them. 



II. 

EQUIPMENT OF A MODERN PATTERN-SHOP. 

The most advantageous arrangement that can be 
given a modem pattern-shop depends upon the floor- 
plan. 

Assuming that the room is rectangular, of ample 
dimensions, and is sufficiently lighted on the sides, 
the most convenient disposition is to place the work- 
benches along one side and the machines along the 
other. By this arrangement the dust and shavings 
can be kept under better control and the trans- 
mission of the power to the machines facilitated. 
Where the dimensions of the floor are about equal 
lengthwise and across, and there is sufficient room 
for the benches along both sides, it is advisable to 
place the machines in the middle or at one end of 
the workshop. A room in which to keep the various 
articles used about the shop by the workmen and 
belonging to the works, such as hand-screws, clamps, 
and other tools, should be partitioned off. It should 
be the duty of the sweeper to see that these articles, 
when not in use, are kept in a place provided for 
them. 

Stands or shelves should be erected at each lathe, 
and the various attachments, such as chucks, cen- 
ters, etc., kept upon them when not in use. Simi- 

13 



14 THE ART OF PATTERN-MAKING, 

lar fixtures should also be provided, where neces- 
sary, for the other machines. 

The line shaft should run from 250 to 300 revolu- 
tions per minute. All wood-working machines 
require high speeds. With a moderately high 
speed to begin with, the necessary speed of the ma- 
chines can be transmitted from the line shaft to 
better advantage than when a lowerer speed of the 
shaft prevails. 

Wood-turning lathes are indispensable in a pat- 
tern-shop, and there should be several of them, their 
number depending on the number of workmen 
employed. In a shop having a force of forty 
pattern-makers at least four lathes are necessary. 
One of these should be a face-lathe for large diame- 
ters, ten feet or thereabouts. Another should be a 
combined face and tailstock lathe, having an ovei*- 
hanging face-plate capable of swinging pieces of about 
six feet in diameter, and a capacity of two feet in 
diameter between the centers. The others should be 
ordinary wood-turning lathes of smaller capacity, one 
of which should be suitable for the smallest work. 
Wooden cones are preferable for wood-turning 
lathes, and they should be carefully balanced. The 
speed for wood-turning may vary from 1200 to 
2500 feet per minute, according to the nature of 
the work. 

In a shop of the foregoing capacity two circular- 
saw machines are necessary, both of which should 
be provided with an iron table and an arrangement 
by which the vertical height of the saw may be 



EQUIPMENT OF A MODERN PATTERN-SHOP. 15 

adjusted. One of these should be capable of receiv- 
ing a saw 28 inches in diameter, and the other a 
saw 14 inches in diaraeter. The smaller machines 
should combine both cross-cut and rip saws, and be 
so arranged that they can be made to ''wabble" 
for rabbeting. 

The usefulness of the machines depends largely on 
the condition in which they are kept. An excellent 
system is to have the teeth of circular saws shaped 
as in Fig. 5, and do all the filing on their front or cut- 
ting sides, the backs of the teeth being spiral curves. 
By this method, when the teeth are all filed equally 
on their fronts, the saw will be reduced uniformly 
in diameter, the amount of reduction depending 
on the spirality of the backs of the teeth and the 
extent of the filing. 

To gum such a saw, a rotary or milling tool should 
be used. There are various neat little machines of 
this kind on the market, using mills of various sizes 
which can be clamped on the saw and the mill re- 
volved by means of a crank, while it is fed to the 
tooth automatically. The mills make a rounded 
throat, which should extend slightly under the face 
of the teeth, so that in filing it will be unnecessary to 
extend the filing to the throat. This method 
requires but little filing to keep the saw sharp. If 
the saw is of sufficient size to admit of the employ- 
ment of a swage for the setting of the teeth, this 
method should be adopted, as with it better results 
can be obtained from the saw than by bending the 
points of adjacent teeth in opposite directions. An 



i6 



THE ART OF PATTERN-MAKING. 



excellent swaging-tool is on the market with which 
the swaging is done by a cam operated with a 
lever. The style of tooth here commended is 
shown at Fig. 5. 




Fig. 5. 

The bearings for the arbor of circular saws should 
be of ample length and babbitted. They require 
careful attention, and should be taken apart and 
cleaned periodically, as it is practically impossible 
to prevent dust working into them. 

Circular saws give good results when running at 
speeds of from 8000 to 10,000 feet per minute. 

Circular saws are usually belted so that the revolu- 
tions of the arbor cannot be varied. In course of 
time saws become worn until their diameters are 
reduced considerably from their original dimen- 
sions; consequently there may be several saws of 
different diameters used on the same arbor, and of 
course their speeds will vary in proportion to their 



EQUIPMENT OF A MODERN PATTERN-SHOP. 17 

diameters. These conditions are met and the best 
results obtained from the machine by driving the 
arbor to the hmit of speed for the largest diameter 
of saw to be used; that is, at about 10,000 feet per 
minute for the periphery of the teeth. 

A handy device for use when dressing saws is 
shown in Fig. 5. It consists of a T frame with the 
horizontal bar secured to a bench. The upright 
has a slot for the vertical adjustment of the saw. 
To the right is a swage, whose pivot can be adjusted 
on the horizontal bar; to the left is a small vise, 7, 
to receive one tooth of a saw. This vise is adjustable 
on the horizontal bar, to which it can be clamped 
by a thumb-screw. By gluing a piece of paper 
around the end of the file and keeping it bearing on 
the shelf while filing, all the teeth can be filed alike 
without difficulty. 

The next most important tool for a pattern-shop 
is the band-saw machine. In a shop of the before- 
mentioned capacity there should be at least two of 
these, one to carry saws up to ij inches wide, and 
the other to carry saws up to one inch. One great 
disadvantage in the use of these machines is the 
want of stiffness in the frames. There are but few 
made which are not deficient in this respect. 

Band-saws give good results when run at a speed 
of 3500 to 4000 feet per minute. These machines 
are usually provided with breaks for the stoppage 
of the saw, and should always be so arranged that 
a pressure on a pulley beyond a certain fixed limit 
cannot be produced by them. If they are not so 



1 8 THE ART OF PATTERN-MAKING. 

provided and the saw is stopped very suddenly, it 
is likely to break in consequence of the strain thus 
created. A great drawback to the use of these 
machines is the cost of the saws, which consequently 
break. That a band-saw will give way in the course 
of time is inevitable. Every time that a saw passes 
over the wheels while running, it bends and straight- 
ens again. This fatigues the material, and with 
continued running it is distressed beyond ultimate 
endurance, just as any similar piece of metal would 
be broken by being bent back and forth a sufficient 
number of times. 

The breakage of saws may be reduced by careful 
attention to their condition and that of the ma- 
chine. In joining them they should be scarfed 
and lapped two teeth and brazed with silver solder. 
Immediately the tongs are removed from the joint, 
a few drops of oil should be dropped on the saw by 
the side of the lap. If not so treated, the saw is 
likely to become too soft on either side of the joint 
and will break there earlier than at any other part. 

Band-saws should always be kept sharp and have 
a proper set to the teeth, and the wooden jaws on the 
guide-bar of the machine should be kept set up close 
to the saw. The mouth-block in the table also 
requires frequent attention, as the deflection of 
the saws, especially the smaller ones, cuts them 
away. 

An excellent little machine for sharpening and 
setting band-saws is to be found on the market. It 
can be secured to a post and occupies little room. 



EQUIPMENT OF A MODERN PATTERN-SHOP. 19 

Being driven by power, a saw can be put in, the 
machine set going and allowed to run without fur- 
ther attention until the saw is finished. 

Another important machine in the pattern-shop 
is a hand-planer. There should be two of these 
machines, one with 16-inch knives, to be kept for 
rough work, the other with 24-inch knives, to be 
reserved exclusively for the cleaner and finer class 
of work, because, if allowed to be used indiscrim- 
inately, the latter will seldom be in the condition 
essential for the kind of work required of it and 
for which the machine is specially adapted. The 
back table of a hand-planer should be provided 
with a locking arrangement, in order that its posi- 
tion cannot be changed after having been adjusted 
to the knives. 

The speed recommended for hand-planers is 
4000 feet per minute, but they will work satisfac- 
torily between that speed and 3500. 

A surface or cylinder planer is also a useful ma- 
chine in a pattern-shop. An improved machine of 
this kind does not require a great amount of atten- 
tion; it suffices to have the knives kept in proper 
condition and the bearings inspected occasionally, to 
see that the oil is properly performing its functions. 

The speed is the same as for the hand-planer. 
When it is difficult to obtain 4000 feet per minute, 
a speed between that and 3500 feet will give satis- 
faction. 

A Daniels planer is very useful in a pattern-shop. 
It is simple, effective and durable, requiring but 



20 THE ART OF PATTERN-MAKING. 

little instruction regarding its care and use. 
With this planer the lumber can be planed out of 
wind, which cannot be done with a cylinder planer, 
although the work is not so rapidly done as with the 
latter. 

The cutters of a Daniels planer should run at a 
high rate of speed, say from 10,000 to 1 1,000 feet per 
minute. The style of cutters recommended for a 
Daniels planer are shaped like the letter J, the cut- 
ting edge being on the side. 

A jig-saw is required in a pattern-shop for inside 
sawing. The band-saw, which has supplanted it 
for outside sawing, is not adapted for positions 
bounded entirely by the material. 

An advisable speed for this machine is from 500 
to 1000 strokes per minute, according to the char- 
acter of the machine. 

A vertical boring-machine is also useful in a 
pattern-shop. One having a capacity for boring 
holes up to 2 inches in diameter is preferable, and 
should be arranged with two speeds, one to produce 
850 or 900 revolutions of spindle, for bits more than 
i\ inches in diameter, the other 1200 or 1300 revo- 
lutions, for smaller bits. 

A core-box machine is another very useful ma- 
chine in a pattern-shop. A machine of this kind is 
on the market, on which core-boxes of any length 
and from f to 20 inches in diameter can be worked. 
Staves and similar pieces can also be worked 
accurately and rapidly on their hollow sides by 
this machine. 



EQUIPMENT OF A MODERN PATTERN-SHOP. 21 

Among the minor power machines that a pattern- 
shop should have are a grinder for planer-knives, 
a wet emery -grinder for bench-tools, and two grind- 
stones, one of the latter being corrugated for the 
convenience of grinding inside bevel gouges. 

Trimmers are indispensable in a modem pattern- 
shop. It is advisable to have at least two of the 
largest size for the general use of the shop, and several 
of smaller size, one being located convenient to each 
two benches. 

There are several other necessary adjuncts to 
the complete equipment of a pattern-shop, but 
these are so well known that description of them 
is here unnecessary. 

The bearings of wood-working machinery require 
very careful attention, in consequence of the high 
speed at which it revolves and their liability to 
the deteriorating effects of dust. Bearings should 
always be provided with tallow-boxes, which should 
be kept filled with tallow or, better, with Albany 
grease. A small hole should be made through the 
grease near each end of the bearing, into which a 
little oil should be dropped before starting the ma- 
chine ; then, should the oil work off with continuous 
running, the grease will continue to keep the bear- 
ing lubricated. 

The foregoing is noted as to machines necessary 
for the equipment of an up-to-date pattern-shop, 
one that should be able to perform with precision, 
expedition, and economy, as far as facilities are con- 
cerned, the work required of it. 



22 



THE ART OF PATTERN-MAKING. 



Of course it is possible to get along, in a manner, 
with less machinery, but such a shop would be 
at a disadvantage when competing with a better- 
equipped concern. 

In many shops a great variety of woodwork is 
done other than that of pattern-making. In such 
establishments additional machinery is necessary, 
the kind and quantity of which will be governed by 
the nature and extent of the work. 

The style of work-bench usually furnished pat- 
tern-makers is the ordinary carpenter's bench, i6 
feet long. Pattern-makers seldom have need of a 
bench more than 12 feet long, and Fig. 6 repre- 
sents a convenient style. 




^<~7y 




T-^ 



4^ 



^ 



|"-.r-vr-vr-vW^^^M-x 



Fig. 6. 
The dimensions of a double bench of this kind, 
well adapted for pattern work, are: 12 feet long, 
4 feet wide, and 3 feet high. For a single bench the 
width should be 3 feet, and the other dimensions 
the same as for a double bench. Each bench should 



EQUIPMENT OF A MODERN PATTERN-SHOP. 23 

have a shelf about i foot from the floor, extending 
over the entire space between the legs of the bench. 
It should also have a drawer for each workman. 
The framing and the top should be of hard wood 
about 3 inches thick, except for about 18 inches in 
the middle of the width of the top; this can be of 
I -inch pine placed flush with the bottom of the side 
pieces, forming a recess in the middle of the bench, 
as illustrated. This recess is convenient for the 
retention of small tools and articles to be used about 
the bench. The jaw of the vise is placed horizon- 
tally, and to it is attached a ratchet bar sliding in 
bearings under the end of the bench. A pawl is 
fitted into the bench over the bar by means of which 
the jaw can be adjusted to suit the work to be 
clamped. This device is shown in detail, marked a. 
The vise-screw is of iron, which works more easily 
than if made of wood. The above arrangement of 
the vise is more convenient than the ordinary ver- 
tical position, as this necessitates stooping on the 
part of the workman in order to attend to the ad- 
justment ; and rather than do this he will often use 
the vise in an awkward position, at the risk of result- 
ing damage. Of late years iron bench- vises are 
becoming much used and are meeting with justly 
increasing favor. 

When sufficient space is available, single benches 
are preferable. With double benches the space 
necessary per workman in the length of the bench 
row is about 5I feet ; with single benches it is about 
6 J feet. 



III. 

THE MANAGEMENT OF A MODERN 
PATTERN-SHOP. 

The qualifications necessary for a foreman to 
possess in order to successfully manage the affairs 
of a large pattern-shop are that he should be a 
draftsman, a good arithmetician, should have a 
thorough knowledge of the art of moulding, and 
should be a good judge of human nature as well as 
of the different materials used in his department. 
He should be able to decide the manner in which 
any pattern is to be moulded, and to direct the 
construction of the pattern accordingly. He should 
also have a thorough knowledge of the construction 
and care of wood-working machinery, and not the 
least of the necessary qualifications are energy, 
good character, and good habits. 

By some persons the pattern-shop is considered a 
drawback to the machine business in consequence 
of the expense because patterns do not show in a 
completed structure as other materials do, and are 
considered unproductive. Yet the pattern-shop is 
more essential than the drawing department, to 
which it is closely allied. It is possible to dis- 
pense with the latter in the machine business, 

24 



My4NAGEMENT OF A MODERN PATTERN-SHOP. 25 

though not with the former where castings are 
required. But unfavorable criticism of the pattern- 
shop is frequently the result either of the critic's 
inexperience in mechanical pursuits, or the assump- 
tion of knowledge that he does not possess. The 
person who invents a method of making castings 
without the aid of patterns has both fame and 
fortune awaiting him. 

The expense attendant on the use of patterns is 
often unnecessarily increased, owing to the abuse 
which they receive in the foundry. Some mould- 
ers are veritable pattern-smashers, and will do more 
damage to a pattern in making a half-dozen castings 
than others will in making a hundred. 

Pattern work, like all other kinds of model work, 
is expensive, and can be made more or less so accord- 
ing to the work required of the pattern. In this 
respect patterns may be divided into three classes, 
and the cost of producing them should be varied 
accordingly. 

a. Patterns of a temporary character, those not 
likely to be used more than once. These should be 
made with as little expenditure of labor and ma- 
terial as possible to enable them to perform their 
functions. These patterns should not be preserved, 
as they unnecessarily encumber the pattern-loft. 

h. A class "of patterns likely to be used occasion- 
ally, sometimes at long intervals. These should be 
preserved, and more pains be taken in their con- 
struction than with the former, as they have to 
withstand the usage in the foundry as well as the 



26 THE ART OF PATTERN-MAKING. 

distortion likely to occur to them during their storage 
in the pattern -loft. 

c. A class of patterns regarded as standard and 
which are frequently used. These cannot be made 
too well, and when properly constructed are neces- 
sarily expensive in first cost. 

When a drawing is received in the pattern-shop 
the first duty of the foreman in connection there- 
with is to acquaint himself with it and decide how 
the pattern is to be made, and in what manner 
moulded. If detail drawings of a machine or other 
device to be constructed are received, a general 
drawing should accompany them, or else the fore- 
man should be made acquainted with the general 
arrangement of the parts. When this is done he 
will often be able to detect errors which might not 
otherwise be discovered until after the castings have 
been made and the machining of them is in progress. 

There are several allowances necessary to be de- 
termined previous to beginning the construction 
of a pattern. The one most troublesome to the 
pattern-maker is that for finishing. The amount 
that will answer for one machinist will not suit 
another. It is advisable to leave as little as possible 
for finishing, and to have sufiicient to allow for the 
proper finishing of the castings. This allowance 
will depend a great deal on the result of the casting 
and its likeness to the pattern. This is likely to 
vary according to the manner of moulding the pat- 
tern. As a rule, the castings requiring the greatest 
amounts for finishing are those which have been 



MANAGEMENT OF A MODERN PATTERN-SHOP. 27 

moulded in loam, and castings made of steel. 
These are liable to vary from the proper dimen- 
sions to a greater extent than those moulded by 
the other methods. Large castings of steel are 
never as true to pattern as those of other metals. 

For patterns to be moulded in loam and for steel 
castings an allowance of from one fourth to one 
half of an inch, according to the part to be finished, 
is necessary. 

For ordinary castings moulded in green or dry 
sand an allowance of from one eighth to one quarter 
of an inch is sufficient. For the smaller castings, 
which have been moulded neatly and are of sound 
metal, an allowance of from one sixteenth to one 
eighth of an inch will answer. 

The allowance for shrinkage, or the amotmt the 
pattern is required to be made larger than the in- 
tended casting, is another important preliminary 
matter to be determined before constructing a 
pattern. The conventional allowance for iron cast- 
ings is one eighth of an inch per foot, but this rule 
needs modification in applying it to castings of 
various shapes, dimensions, and mixtures of metals. 
To insure accuracy in castings much depends on 
the judgment of the pattern-maker in providing 
for their construction. Hard irons, as gun-iron, 
will shrink more than the above amotmt, while soft 
iron will shrink less. Yellow brass will shrink more 
than bronze. A plain cylinder will shrink less in 
diameter than in length. 

With large cylindrical or box-shaped castings 



28 THE ART OF PATTERN-MAKING. 

of iron it is good practice to allow one tenth of an 
inch per foot for shrinkage in length, and one half of 
this amount in diameter, or across. The shrinkage 
in length of such castings is generally very little 
restricted, while in diameter it is resisted by the 
cores or internal parts of the mould. Two castings 
of the same weight and of the same kind of material, 
one of which is extended and the other more com- 
pact, will shrink differently, the latter shrinking 
less than the former. 

Metals, like water, are densest in their liquid 
state, the point of greatest density being near the 
temperature at which they solidify. From this 
point they will expand either with a reduction or 
an elevation of temperature. Iron, when about to 
solidify, undergoes a sudden expansion, owing to 
the effort of the molecules to arrange themselves 
in definite positions. After solidification takes place 
it begins to contract, with a further loss of tem- 
perature. When the contraction begins, the metal 
is just leaving its plastic condition, and its cohesive 
strength is considerably below that of its normal 
state. If at this period the contraction of the metal is 
resisted by parts of the mould, a fracture of the metal 
is likely to occur. With some of the more contracti- 
ble metals, as with steel, to avoid fractures it be- 
comes necessary, as soon as the metal has set, to 
relieve the interior parts of the mould and allow 
the metal freedom in shrinkage. In the case of a 
plain cylinder, where its shrinkage is resisted by an 
internal core, the metal will contract within its 



MANAGEMENT OF A MODERN PATTERN-SHOP. 29 

annular wall until its cohesive strength becomes 
sufficient to compress the core, at which period it 
will have undergone part of its contraction. This 
accounts for the reduced shrinkage of cylinders 
diametrically. 

The usual allowances for the shrinkage of castings 
of different metals are, per foot : 

For iron one eighth of an inch. 

" bronze five thirty seconds of an inch, 

" brass three sixteenths of an inch. 

" yellow brass seven thirty seconds of an inch. 

" steel three sixteenths of an inch. 

" aluminum seven thirty-seconds of an inch. 

" zinc seven thirty-seconds of an inch. 

" lead seven thirty-seconds of an inch 

" tin three sixteenths of an inch.' 

It is not always known where the castings for 
which a pattern is to be constructed are to be made. 
The opinions of moulders will differ widely as to the 
best method of moulding some patterns. In such 
cases the foreman is often perplexed. His desire 
should always be to have a pattern made to be 
moulded to the best advantage of the f oundryman. 
Where there is any doubt as to the best way of 
moulding a pattern, the foreman moulder should 
be consulted where it is possible. As he is respon- 
sible for the proper production of the castings, his 
desire should be regarded and the pattern made 
for his convenience. 

It is too often the case that strained relations 
exist between the heads of the pattern-shop and 
the foundry in consequence of the perversity of 



30 THE ART OF PATTERN-MAKING. 

one or the other, or through attempts made to shift 
responsibiUties. Each should desire harmony in 
their business intercourse, because without this 
the work cannot be carried on to the best advantage 
of their employers. 

The foreman of a pattern or any other shop should 
be relieved of any clerical work. His proper place 
is in the shop among the workmen, observing what 
is going on ; to inspect and direct the work in prog- 
ress ; to see that every employee is performing his 
duty properly, and that the materials and machin- 
ery are properly used. When he performs all this, 
he will have little time to devote to office work. 
With pattern lumber at from seven to ten cents per 
foot, and where large quantities are being used, it is 
an important part of a foreman's duty to see that it is 
economically employed. The repairs to machines, 
belting, etc., and the sharpening of cutters is quite 
an item in the running expenses, and the desire 
should be to reduce this to a minimum. 

A foreman should have full control of the em- 
ployees in his shop as long as he is held responsible 
for its management. Without this it is probable 
that by some he will not be respected as he should 
be. He should be gentlemanly in his intercourse 
without being too familiar with his subordinates, 
and should insist on being respected by them. In 
some instances the responsibility of employing and 
discharging employees, as well as other duties 
which should belong to the foreman, are assumed 
by others above him. Where such a condition 



MANAGEMENT OF A MODERN PATTERN-SHOP. 31 

prevails, the inevitable tendency is to impair the 
efficiency of the shop, and it behooves the foreman 
to use his judgment very discreetly if he desires to 
reduce to a minimum the annoyances inseparable 
from such a system. 

One thing that reflects credit on the management 
of a pattern-shop is to have it look clean and tidy. 
Of course it is impossible, where so many shavings, 
etc., are made, to have such a shop look as clean as 
some other kinds of shops. However, it can be kept 
reasonably clean without an excessive amount of 
labor by a proper system, making it the business of 
a person to clean the shop. What helps to make a 
pattern-shop look untidy is the accumulation of 
scraps, etc., that litter the floor under the work- 
benches, thrown there by the workmen for future- 
use, but who seldom trouble themselves to look 
through the lot when it is easier to cut a board. 
This accumulation is aided by the unsuitableness 
of the ordinary carpenter's work-bench, which is 
the kind usually supplied to pattern-makers. With 
the style of bench previously illustrated and de- 
scribed, having under it a shelf about one foot from 
the floor for the reception of articles not wanted 
for immediate use, the space under the bench can 
be swept clean and accumulation of rubbish pre- 
vented. 

It is too frequently the case that work-benches 
are unnecessarily abused. Some workmen will 
use the bench-stop while sawing and thereby risk 
cutting into the top and vise rather than take the 



32 THE ART OF PATTERN-MAKING. 

trouble of making a bench-hook. The undue dis- 
figurement of a work-bench is infalhble evidence 
that it has been occupied by a careless and slovenly 
workman. 

The machines in the pattern-shop most likely 
to cause accidents, as well as to be misused, are the 
circular saw and the hand-planer. When workmen 
are careless or ignorant of the use of machines they 
should be instructed how to use them properly. No 
saw should ever be forced beyond its limit for doing 
good work. Even a good saw in the best of con- 
dition can be made to work unsatisfactorily by forc- 
ing the work too hard upon it. In using a circular 
saw a person should never place his hand behind 
it while standing in front, nor even let the hand pass 
in front of the saw while so standing. A stick should 
be kept handy, and when the end of the work is near 
the saw, finish by pushing it through with the stick. 
Should the saw incline to run out when not forcing 
it, withdraw the work and investigate the cause, 
which will likely be one of the following : a dull saw 
or one with insufficient set. Should the work spring 
and bind on the saw, withdraw it at once and begin 
sawing at the other end, or else have some one insert 
a wedge after the end has passed the saw. Many 
deaths have been caused by the board being sawn, 
binding on the back of the saw, which causes the 
board to be raised until the top of the saw comes in 
contact with it and throws it forward with great 
force. 

The band-saw is not considered a dangerous tool, 



MANAGEMENT OF A MODERN PATTERN-SHOP. 33 

but it is liable to great abuse by the use of saws 
that are too dull or insufficiently set, or by attempt- 
ing to saw curves smaller than those in which the 
saw will freely turn. 

Nearly every accident occurring on the hand- 
planer is caused by attempting to plane short pieces 
which, before they are made to bridge the mouth of 
the planer, are caught by the knives and drawn in. 
Often a hand goes in with the piece of work, and the 
person is maimed for life. A good rule to be ob- 
served in using this machine is never to attempt to 
plane a piece of work on it less than lo inches long 
nor less than f of an inch thick. 



IV. 
PATTERN WORK FOR MOULDING IN LOAM. 

The present chapters have not been written with 
the view of teaching the art of pattern-making, but 
rather presuppose a knowledge of it; proficiency 
must be acquired by practical work, patient applica- 
tion, and the stimulus of ingenuity at the drawing- 
board, bench, and lathe. Aided even by the exer- 
cise of these qualifications, only they who possess 
natural aptitude and who labor long for success can 
hope to achieve their object and become expert in 
their profession. 

The examples given have been selected from 
many cases of actual practice, have all borne satis- 
factory results, and are therefore considered reliable. 
They are given for the purpose of awakening 
thought and with the desire to encourage independ- 
ent suggestion and inventive power; for this will 
be the surest pathway to a knowledge of the best 
methods of constructing patterns that will satisfy the 
varied requirements of the moulder. 

In a shop employing a large number of workmen 
and doing a great variety of work there will always 
be found those who excel in a particular kind of 
work. Some will be more expert in one class and 
others in another. In the giving out of work it 

34 



PATTERN JVORK FOR MOULDING IN LOAM. 35 

is well to consider the efficiency of the workmen in 
this respect, and, as far as possible, to make a judi- 
cious distribution. 

When giving out a job the foreman should express 
to the workman his opinion as to how the pattern 
should be made and moulded, but he should also 
listen to and consider any suggestion made by the 
workman regarding it. Should the workman desire 
to make the pattern in a different way from that 
suggested by the foreman, and if a result equal in 
efficiency and economy can be thereby accom- 
plished, he should be allowed to proceed in his own 
way, as he will then probably feel a greater interest 
in producing a good result. 

Many good workmen consider it humiliating not 
to be allowed to use their own judgment as to the 
manner in which a piece of work should be done, 
and it is good policy not altogether to disregard 
their opinions unless they are manifestly at fault, 
but rather through an interchange of opinion arrive 
at a mutual understanding. 

Men should be dealt with as men, and boys as 
boys, and not the reverse, which is sometimes at- 
tempted. 

Loam moulding is resorted to when the article 
wanted is of too large dimensions or is too compli- 
cated in form to be moulded by any other method, or 
when the casting is not likely to be often duplicated. 
It is considered the most intricate, varied, and expen- 
sive method of producing castings, whether of iron, 
brass, or steel. On the other hand, the pattern 



36 



THE ART OF PATTERN-M/tKING. 



work for loam moulding, while often very intricate, 
is of the most inexpensive kind- 
Patterns for loam moulding are both of the sim- 
plest and the most complicated kind. The sim- 
plest are for bodies of revolution, or those objects 
which can be formed by revolving a radial section 
of the body about an axis. One of the simplest 
examples is the pattern work for a large plain kettle. 
These comprise a number of sweeps or strikes, in 
some places called strickles. A sweep consists of a 
plain piece of board whose profile is that exposed 
by a plane cutting the body parallel with and pass- 
ing through its axis. 

The first sweep used in constructing a mould for 
a kettle is that marked A, Fig. 7. It is secured to 




the spindle, a, which is free to revolve about a 
vertical axis. The mould is built up of brickwork. 



PATTERN JVORK FOR MOULDING IN LOAM. 



37 



with a thickness of loam intervening between it 
and the edge of the sweep, and, when the latter is 
revolved, it strikes or dresses the loam off to the 
form of the sweep. This part of the mould, when 
completed, is called the core, and forms the inside 
of the kettle. 

The next sweep is used to form the thickness of 
the kettle. This is marked B, Fig. 8, and it super- 



a 




sedes sweep A on the spindle. Prepared moulding 
sand, b, is placed around the core and is swept to 
the outside form of the kettle by revolving the 
sweep. This concludes the function of the pattern 
work necessary for the job. The moulding is con- 
tinued by building up brickwork, strengthened 
with plates, with a thickness of loam intervening 
between it and the moulding-sand thickness. 

When it is of great importance to insure a dense 



38 THE ART OF PATTERN-MAKING, 

and solid bottom the kettle is moulded in the re- 
verse position, bottom down. This is a somewhat 
more expensive method than the former. When 
moulded the latter way the sweeps are made the 
reverse of those described, and are used in the 
reverse order. 



V. 

Px\TTERN WORK FOR A CYLINDER. 

Large cylinders, with nozzles such as are used 
in beam engines, are objects well adapted to be 
moulded in loam. They require somewhat more pat- 
tern work than the former example. Fig. 9 repre- 
sents a section of mould for a cylinder of this kind. 

When preparing the pattern work for such a cylin- 
der the first piece required by the moulder is the 
sweep. Fig. 10. This is used to form the seat or 
foimdation of the mould. After the seat has been 
swept up and the sweep removed the seat is lined 
off. The segment. Fig. 11, is the next in order, 
and is made of board the thickness of the bottom 
flange of the cylinder and having an inside radius 
equal to that of the outside of the flange. It is set 
as illustrated, and moulding sand is rammed inside 
of it to form the pattern of the lower flange of the 
cylinder. 

The next piece in order used is the outside or 
cope sweep, Fig. 12. This being secured to the 
spindle, everything is prepared for the building of 
the outside of the mould. The patterns of the noz- 
zles. Fig. 13, being prepared, they are set by lines 
in their proper positions during the building of the 
outside of the mould. The outside flange seen on the 

39 



40 THE ART OF PATTERN-MAKING. 

a 



^^ 



Fig. 13 




Fig. 15. 



Fig. 10. 



Fig. II. 




a 




Fig. 12. 



&^ 



Z 



3 



1 



Fig. 9. 



Fig. 14. 



PATTERN fVORK FOR A CYLINDER, 41 

nozzle pattern is to form a seat for a covering- plate. 
These plates have holes through them, through 
which the nozzle-cores pass. The outside wall, or 
cope, of the mould being finished as far as the top 
of the upper flange and the sweep. Fig. 12, removed, 
the cope is then removed from the seat, leaving the 
latter intact. 

The main core sweep. Fig. 14, is next attached 
to the spindle, as illustrated. When the cylinder 
is a very long one, it is advisable to make this sweep 
in two pieces, batten them together and apply an 
additional spindle-arm, h, above the batten. When 
the core has been built up above the joint in the 
sweep, the lower part of the sweep, as well as the 
extra spindle-arm, can be removed and the building 
of the remainder of the core proceeded with. The 
core is extended about one foot above the top flange 
for the purpose of providing for a head to be cast 
on the top of the cylinder to receive the impurities 
of the metal and insure the solidity of the upper 
part of the casting. When the main core is com- 
pleted it is left standing on the seat and dried in 
that position. 

The cope plate, /, is next prepared, and is usually 
a cast-iron plate, one side of which is provided 
with prickers. This side is covered with loam and 
swept off with a straight sweep. When dry it is 
inverted and the mould extended on the upper side 
and made to form the outer wall of the head. The 
mould, when completed, presents an annular open- 
ing at the top, through which the metal is poured 



42 THE ART OF PATTERN-MAKING. 

and drops to the bottom. Fig. 15 is the core-box 
for the nozzle-cores, and Fig. 9 represents a section 
of the mould when assembled. 

A column of cast iron 3.84 inches in height and 
of one square inch in area weighs one pound and 
exerts that pressure per square inch on its base 
when in a liquid state. 

Assuming the foregoing cylinder to be 16 feet or 
192 inches in height from the bottom to the head, 
the pressure will consequently be fifty pounds per 
square inch on the bottom of the mould. This 
great pressure has a straining effect on the mould — 
a tendency to separate its walls. If the walls of 
the mould are parallel with each other, that is, 
have a uniform distance between them from top 
to bottom, the casting would probably show a 
greater thickness of metal at the bottom. It is 
advisable, therefore, to set the sweeps to counteract 
this straining of the mould by the metal. 

For a cylinder 10 or 12 feet in height the core 
should be made one eighth of an inch larger in 
diameter at the bottom than at the top, and the 
outer wall one eighth of an inch smaller in diameter 
at the bottom than at the top. The mould would 
then measure one eighth of an inch less between its 
walls at the bottom than at the top, but the thick- 
ness of the casting would most likely be uniform, 
owing to the straining effect of the metal on the 
mould while being filled. For a cylinder of 15 or 18 
feet in height this difference between the walls of 



PATTERN IVORK FOR A CYLINDER. 43 

the mould at the top and the bottom can be increased 
to three sixteenths of an inch. 

The result of pressure on the liquid metal in a 
mould is to increase its density and strength when 
cold. In some instances moulds are arranged to 
receive a pressure in addition to that produced by 
the metal alone, as in the case of the Whit worth 
process of casting steel. Even should the mould 
not be strained to the extent allowed for, the cast- 
ing will be strongest at the bottom, owing to the 
benefit resulting from the greater pressure there. 



VI. 
PATTERN WORK FOR AN ELBOW. 

In constructing loam moulds it is not always 
necessary to have a spindle. Other bodies than 
bodies of revolution can be swept up in loam when 
the necessary guides are provided for the sweeps. 
Figs. i6 to 31 represent a large valve-chamber com- 
bined with a nozzle, or elbow, or bend. Fig. 16 is a 
frame made of |- or i|-inch material. The interior 
of the frame corresponds with a horizontal section 
of the casting. The size of the opening at each 
end is extended in the frame for the same purpose 
that core-prints are made to form a seat, or support, 
as well as a guide for setting the core. The outside 
of the frame is worked off, to be parallel with the 
inside, for the purpose of forming a guide for the 
sweeps. Fig. 17 is the pattern for the flange at 
the valve-chamber end; Fig. 18 that of the end of 
the bend; Fig. 19 is the pattern to form the bell 
shape where the diameters change; these are 
shown attached to plate 16. A pattern for this 
part is not absolutely necessary, as it can be 
formed by sweeps; but a pattern facilitates the 
moulding; Fig. 20 is the pattern for the branch, 
or nozzle; Fig. 21 is the sweep to form the outside 
of the mould at the bottom or drag part of the 

44 



PATTERN IVORK FOR AN ELBOJV. 



45 



bend, and Fig. 22 that for the inside; Fig. 23 is the 
sweep to form the outside of the mould in the drag 
for the chamber, and Fig. 24 that for the inside; 
Fig. 25 is the sweep for the core-print of the drag 
at the valve-chamber end, and Fig. 26 is the sweep 
for the core on the cope side of the bend; Fig. 27 
is that for the outside of the bend; Fig. 28 is the 




Fig. 16, 




» Fig. 16. 



Fig. 18. Fig. 19. Fig. 17. 

sweep for the inside, or core, of the chamber on the 
cope side, and Fig. 29 that for the outside; Fig. 30 
is the sweep for the core -print on the cope side. 
All of the necessary pattern work being prepared 
as described for the construction of the mould, its 
building can be proceeded with. 

A foundation-plate is first prepared, upon which 
the mould is to be built. The frame. Fig. 16, with 



46 



THE ART OF PATTERN-MAKING. • 



the lower or drag parts of the pattern screwed 
thereto is set up on the plate, and brickwork of 
the usual kind for loara moulding is built up to the 
frame, P'ig. 16. While building up the mould the 




Fig. 20. 



Fig. 25. 




Fig. 28. 




Fig, 29. 




Fig. 30. 





Fig. 21. 



Fig. 23. 





Fig. 22. 



Fig. 24. 





Fig. 26. 



Fig. 27. 




Fig. 31. 



proper sweeps are used. The sweep Fig. 21 is 
used to form the outside of the mould by moving it 
around the bend with the semicircular part pro- 



PATTERN IVORK FOR AN ELBOJV. 47 

jecting downward and the straight parts resting 
on the frame, while the projection on the end of 
the sweep is kept bearing against the edge of the 
frame. The sweep Fig. 23 is used in a similar 
manner to form the outside of the chamber. The 
sweep Fig. 22 is used like Fig. 21, to form the core- 
seat at the end of the bend. 

The mould for the outside of the casting being 
finished on the drag side, it is then dried, after 
which a thickness of green sand equal to that of 
the metal is worked around the inside of the mould, 
as shown by dotted lines, the sweeps Figs. 22 and 24 
being used for the purpose in a manner similar to 
that of Figs. 21 and 23. The thickness being com- 
pleted, the core is made on the inside up to the top 
side of the frame. The patterns for the upper or 
cope part of the flanges, Figs. 17 and 18, also that 
for Fig. 19, are placed in their proper positions, 
and the building of the core is continued on the 
cope part of the mould, the sweeps Figs. 26 and 28 
being used to reduce the core to its proper shape. 
After the core is completed, green sand equal in 
thickness to that of the metal is worked around 
the outside of the core, and the sweeps Figs. 27 
and 29 used to reduce it to the form of the outside 
of the casting. The core-print on the cope side at 
the chamber end is formed by the sweep Fig. 30. 
The branch or nozzle, Fig. 20, is now set in its proper 
position on the pattern as formed. The core of 
the nozzle, which is made within the latter, is made 
to connect with the main core. The mould is then 



4^ THE ART OF PATTERN-MAKING. 

completed by the building up the cope half. The 
nozzle is made to be withdrawn from without, and 
a loam plate is made to cover the flange of the nozzle. 
When the mould is disjointed, the impression made 
by the frame. Fig. i6, is filled in. 

Nozzles are made to set at various angles on the 
chamber. In some cases more than one is cast on 
it. It will sometimes be advisable to make the 
nozzle pattern solid, with core-print attached, and 
have a separate core for it. 

Fig. 31 illustrates the mould in part section 
when its building up is completed. 



VII. 

PATTERN WORK FOR STEAM-CYLINDER 
OF MARINE ENGINE. 

The pattern of a large steam-cylinder, with steam- 
and exhaust-passages, when moulded in loam, de- 
mands a greater proportionate amount of detail 
than is required by those described already. The 
pattern work can be made more or less elaborate, 
according to the manner in which the moulder 
desires to proceed in order to construct the mould. 

The following pattern work and method of pro- 
cedure have been applied with successful results in 
producing satisfactory castings of large cylinders. 

Fig. 32 shows a plain view. Fig. 33 an elevation, 
and Fig. 34 a section of a casting designed for a 
low-pressure cylinder with receiver for a compound 
engine. 

When a loam mould is to be made for such a 
cylinder the pattern-maker is required to prepare 
the necessary pattern work before the moulder can 
proceed with its construction. 

The cylinder is moulded inverted; that is, the 
open end, or that which is upward when it is in the 
engine, is moulded downwards. 

The first piece required is the seat, or foundation 
sweep, Fig. 35. This sweep forms a level surface, 

49 



so 



THE ART OF PATTERN-MAKING, 




ri 


n 




, ,7 




:: .r^-_-_-_-_-_---||r :r= r_-_-_-z 




1 j 


J 




s 


"=^ 


\ 




j 








1 1 1 




:: :-3-r--^z{l --^--^^± 




/ \ 






J 





Fig. 32. 



Fig. 33. 



Ff5 



V, 



ar 



an 



a\z 




>;i^3 



^ 



Fig. 34. 



Fig 35. 




c 






1 


... vy 




) 










\ 
\ 

V 




d 




d 


i 




1 








/ 


cZ 




d 













) 




Fi 


1.1. 


36. 


* 










e 



Fig. 37. 



STEAM-CYLINDER OF MARINE ENGINE. 



51 



Fig. 38. 




Fig. 39. 



t 




ST 



^2 




Fig. 40 




I 







Mi 




Fig. 43. 




H 




Fig. 42. 




Fig. 41 

P 



i 



^ 






Fig. 44. 



Fig. 45. 



52 THE ART OF PATTERN-MAKING. 

Upon which the pattern work is -placed ; and it also 
forms the flange facing, against which the cylinder- 
head is bolted. Fig. 36 represents a framework of 
wood. Its exterior is the form of the exterior of 
the casting. It also contains the valve-chest, 
which is the same in form as that represented in 
the sectional view, Fig. 34, except that where the 
openings are shown in the valve-face core-prints are 
placed, as shown by the dotted lines a, a, etc., pro- 
jecting from the valve-face. These core-prints 
are for the purpose of locating and supporting the 
cores for the induction and eduction passages. 
The cylindrical parts can be formed with revolving 
sweeps, secured to a spindle, which method is pre- 
ferred by some moulders ; but a framework of wood 
is preferable in cases of this character, as with it there 
is less difficulty in retaining the parts in their proper 
positions. The flanges projecting inward in the 
valve-chest are screwed or put on with draw-pins, 
in order that they may be released and withdrawn 
outwardly. The framework is made in sections and 
screwed together to facilitate its being taken apart 
and withdrawn from the mould. The patterns 
for the exhaust-nozzle h and nozzle c are made 
blank and cored out with special cores inserted 
from the outside of the mould. 

The foundation, or seat, being prepared and lined 
off, the framework is placed upon it and properly 
located. Everything is then prepared for the 
building of the cope, or outer wall of the mould, 
to be proceeded with. The framework has open 



STEAM-CYLINDER OF MARINE ENGINE. 53 

places, as d, d, etc. When the mould is being 
built up past these places, a strike, e, is used 
from the inside to shape these parts of the mould. 
When the exterior of the mould is completed to the 
top of the upper flange it is struck off by a plain 
sweep fixed at right angles to the spindle. A line 
is drawn across the top of the mould through the 
center of the cylinder and valve-chest, and another 
line at right angles to the former and through the 
axis is also scribed on the top of the mould. These 
lines are for the purpose of locating the position of 
the covering-plate of the mould. When the exterior 
of the mould, which has been made in sections, is 
sufficiently dry to handle, it is removed from the 
seat, leaving the latter intact. 

The framework is then removed from the seat, 
after which the main-core sweep. Fig. 37, is se- 
cured to the spindle and the main core built up on 
the seat, where it is dried and dressed and remains 
undisturbed. A core-seat is formed in the upper 
part of the main core, into which a core is set to 
core out the hole in the head of the cylinder for the 
plug which contains the stuffing-box for the piston- 
rod. Previous to setting the core the main core is 
filled with sand, as a precaution against accident, 
the metal being liable to make its way into the inte- 
rior of the core during the filling of the mould. 

The cover of the mould, or cope-plate as it is 
sometimes called, is made to form the head of the 
cylinder. It is a plate provided with prickers, and 
is specially cast for the purpose. When preparing 



54 THE ART OF PATTERN-MAKING. 

the mould upon it it is inverted, as shown in Fig. 
39, and a spindle is erected at its center. The 
sweep Fig. 38 is secured to the spindle, and a sur- 
face conforming to the shape of the top of the ribs and 
flange of the cylinder-head is swept up. The parts 
of the casting which project beyond this surface, 
such as the flange of the stufling-box for the valve- 
stem and the brackets by which the cylinder is 
secured to the housing, are represented by patterns 
which are accurately located and bedded into the 
loam during the sweeping up of this surface by the 
sweep Fig. 38. The patterns for the nozzle for the 
stuffing-box plug and the radiating ribs being pre- 
pared, they are properly placed upon the surface 
last swept up, and another sweep. Fig. 40, is employed 
to sweep off the top of the cores. The ribs for the 
cylinder-head, with the sweep Fig. 40, are shown 
apart from the plate at Fig. 41. When the mould 
on the plate is finished it is marked with lines at 
right angles to each other to correspond with those 
scribed on the top of the exterior of the mould. The 
covering-plate is set on the mould by these lines. 

The core to form the receiver, or that part of the 
casting between its inner and outer walls, in some 
cases is the usual brickwork of loam moulds; in 
other cases a series of cores made in a box and joined 
together to form the required part are used. This 
latter method is preferable, as it possesses the merit 
of being much more easily cleaned out of the cast- 
ing, although greater care is required in preparing 
the vents. 



STEAM-CYLINDER OF MARINE ENGINE. 55 

At Fig. 42 are shown three views of a core-box 
for receiver cores. The cyHnder herein described 
will require eight of these cores, two in height and 
two around each side. The box is made a segment 
of ninety degrees, but the cores complete will not 
extend so far. They are made the required size 
and shape to fit the mould by placing stopping-off 
pieces in the ends of the box. / shows such a piece 
for stopping off the cores. Where the exhaust 
emerges it requires two of these pieces, one right- 
and one left-hand. Two more of the proper form, 
right and left, are required to stop off the cores which 
go to the open side opposite the valve-chest. Fig. 
43 represents the box in which the core for the 
exhaust-passage is made. Three views are shown — 
plan, elevation, and section. The box is made to 
be taken apart. 

Fig. 44 shows the box in which the cores for the 
steam-passages are made. These passages are of 
the double-ported variety. Three views of these 
are shown — plan, elevation, and section. Fig. 45 
represents the core-box for coring out the cylinder- 
head nozzle, into which is fitted the plug containing 
the stufQng-box for the piston-rod. 



VIII. 
PATTERN WORK FOR A PEDESTAL. 

Occasionally a large casting of some kind is called 
for, a duplicate of which is never likely to be re- 
quired. To make in the usual way a pattern for 
such a casting would consume considerable time, 
which might cause delay as well as involve -unneces- 
sary expense. In such cases, therefore, recourse is 
had to temporary expedients. Fig. 46 shows such 
a casting in the form of a tapered pedestal, whose 
length and comparatively small diameter are such 
as to make it inadvisable to sweep it up vertically, 
after the manner of making a cylinder mould, or to 
incur the expense of constructing a pattern of the 
usual kind. It being decided to cast the pedestal 
in a horizontal position, a barrel, upon which the core 
is made, is the first piece required. The pattern of 
the core-barrel will be formed by strikes, or sweeps, 
guided by proper templet, the skill of the moulder 
being called in to form the pattern after the pattern- 
maker has provided the necessary appliances. Fig. 
47 illustrates a section of the mould and pattern for 
the core-barrel. An iron flask is first constructed 
which, when very long, as in the present case, is made 

in two pieces. The usual brickwork of loam moulds 

56 



PATTERN IVORK FOR A PEDESTAL. 57 

is built inside the flask, and the guide a is set at 
one end of the drag, the guide / at the opposite end, 
and guide c midway between the two. When thus 
arranged, their circles are such that when a straight- 
edge is moved around the inside, the required uni- 
form taper will be produced. The middle guide is 
not absolutely essential, but with it the strike need 
be only one half the length of the mould, thus being 
more conveniently handled, h is the sweep for 
forming the lower or drag half of the mould, and 
being half the length of the latter, it is used alter- 
nately at each end. The recess in the mould formed 
by the offset on the sweep h represents the thickness 
of the casting. When the mould is sufficiently dry 
this recess is filled in with green sand, and a straight- 
edge moved around the guides reduces it to the 
proper thickness. This last operation completes 
the lower half of the mould and pattern. The core 
is next made on the inside of the mould up to the 
joint. The guide h having been set in a, and g in /, 
these determine the diameter of the upper half of 
the core. The half -collar d is set midway between 
the other two for the convenience of a guide for the 
sweep, which is a straight-edge, of half the length 
of the mould. When the core is formed the collar d 
is removed and its impression in the core filled in. 
The core being sufficiently dry, the half -collar d is 
set midway of its length, and green sand is placed 
aroimd the core ; the sweep i is then used to reduce 
the sand to the thickness of the intended metal. 
This completes the core and pattern for the upper 



58 



THE ART OF PATTERN-MAKING. 







Fig. 46. 



Fig. 49. 







[3 



d 



I t^-^ 




Fig. 47. 



[Of 






7? 










_-_. 1 


'--t 


J. q 


" 


F -i. 



Fig. 48. 



PATTERN IVORK FOR A PEDESTAL, 59 

or cope half of the mould. The mould is then com- 
pleted in the usual manner. The illustration shows 
the various guides and sweeps for the core in the 
relative positions which they occupy in the mould, 
but separated from it. 

When the mould is taken apart and the core 
lifted out, the thickness of green sand is removed, 
and the mould and core are then finished in the 
usual manner. Numerous small cores, the same 
length as the thickness of metal, are fixed around 
the mould for the purpose of casting holes in the 
core-barrel. The core-barrel k, being cast, is mounted 
between bearings, as illustrated at Fig. 48. The core 
is made in the usual manner by winding the barrel 
with rope made of hay, then coating this with loam, /, 
and reducing the loam to the required size and 
shape by revolving the core while in contact with 
one side of the sweep n, which is so set as to obtain 
the proper diameter of the core. 

When the core is sufficiently dry, which is accom- 
plished by building a fire imder it while it remains 
in the bearings, a second coat, w, of specially pre- 
pared loam is laid on and brought to the required 
thickness, which is equal to that of the metal, by 
revolving the core, while the reverse edge of the 
sweep n is fixed so as to reduce the loam to the re- 
quired diameter. This being accomplished, the 
second coat forms the pattern for the body of the 
pedestal. When this outer coat is dry and dressed 
it is ready to receive the top and bottom flanges, 



6o THE ART OF PATTERN-MAKING, 

Fig. 49, ribs, bosses, and whatever else is necessary 
to complete the pattern. 

These parts are made of wood, and are fitted to 
the pattern formed for the body of the pedestal, 
the flanges parting through their center and the 
bosses arranged so that they can be drawn in through 
the vacancy left by withdrawing the flanges. 

The pedestal pattern is supported in a horizontal 
position when it is being made, the supports being 
under the gudgeons which project from the ends of 
the core-barrel. The mould is constructed of 
brickwork in the usual manner of constructing 
loam moulds. When the mould has been com- 
pleted and taken apart the coating of loam repre- 
senting the thickness of metal is removed from the 
core and the latter dressed. After the mould has 
received like treatment it is reassembled. 



IX. 

PATTERN WORK FOR SCREW PROPELLERS 
WHEN SWEPT UP IN LOAM. 

One of the most interesting objects swept up in 
loam, and which to be successful requires considera- 
ble skill and experience on the part of the pattern- 
maker and moulder, is a large screw propeller cast 
entire. 

Figs. 50 to 56, inclusive, show the preparations 
necessary to be made by the pattern-maker when 
the mould of a large screw propeller is intended to 
be swept up in loam. 

Fig. 50 represents the guide, or directrix, upon 
which the blade-face, sweep, or generatrix travels 
to produce the helicoidal surface. The guide is 
usually set six inches beyond the periphery of the 
blade, to allow for the joint of the mould. 

At one time guides were made of plate-iron cut to 
the proper angle and secured to a base of wood after 
being bent to the required curvature. The term 
*' guide-iron" was derived from this method of mak- 
ing them. A guide made entirely of wood is, how- 
ever, preferable. 

Fig. 51 illustrates how the curvature of the guide 

ma}^ be obtained. An arc of a circle of the radius 

of the position of guide from the axis is described 

61 



62 THE ART OF PATTERN-MAKING. 

for the base. The degrees of the arc should be 
somewhat greater than the angle occupied by the 
blade when it is viewed parallel with the axis, in 
order to allow for a joint at both the top and bottom 
edges of the blades. The arc is divided into any 
number of equal parts, as a, h, and c. The length 
of the inclined rail is obtained by laying down its 
angle with one end intersecting one extremity of 
the base line, and the other end intersecting a per- 
pendicular from the other extremity of the base. 
The length of the rail is divided into the same num- 
ber of equal parts as the base and ordinates of like 
letters made equal in length. A curve drawn 
through the extremities of the ordinates will be the 
elliptic arc, to which the rail is to be worked. In 
constructing the guide, the rail is left sufficiently 
wide to allow for finishing the top edge, which is the 
last work done on it. To lay off the guide a line is 
described parallel with the base and about four 
inches from the bottom, which is to allow for a joint 
in the mould. The length of this line, or arc, will 
be that intersecting radial lines which are tangent 
to the edges of the blade when it is viewed parallel 
with the axis. The arc is divided into equal parts, 
and it is advisable to have one of the intersections 
in the center, to be used as a center line. Per- 
pendiculars are erected from the intersections, and 
the length of the ordinates for the angle of the guide 
laid off on them. A thin strip, or batten, is then 
tacked on the inside of the rail, intersecting the 
extremities of these ordinates. A line drawn along 



SCREIV PROPELLERS IVHEN SIVEPT UP IN LOAM. 63 

the top of the batten on the rail will be the guide 
line. The rail is to be worked off to this line, a try- 
square, with the stock held vertically, being used to 
gauge the shape of the edge. 

For a screw of uniform pitch the guide line 
developed on a plane is a straight line. For a 
screw of expanding or increasing pitch the line 
developed is a curve, the ordinates for which should 
always be given on the drawing. 

Fig. 52 is a thickness piece representing a section 
of the blade at the first division from the hub, and 
Fig. 53 represents a similar section, the first divi- 
sion from the periphery. These should be made of 
pine board about three fourths of an inch thick, and 
are curfed with a saw for about three fpurths of their 
thickness. The curfs are made parallel with the 
axis of the screw, and the distance between them 
should be such as to permit the thickness pieces 
being bent to the line marked for them on the pier 
by the notches in the blade-face sweep. The thick- 
ness pieces are secured to the piers with nails. 

Fig. 54 is the sweep for the foundation, or seat; 
Fig. 55, that for the hub; and Fig. 56, the sweep for 
the generatrix, or face of the blades. Sweep Fig. 56 
is made of plain board about i\ inches thick. The 
generatrix, or working edge of the sweep, is made of 
various shapes, according to the ideas of the de- 
signer. In the present case it is a right line per- 
pendicular to the axis of the screw. The distance 
between the hub and the periphery is divided into 
as many parts as there are thickness pieces to be 



64 



THE ART OF PATTERN-MAKING, 





Fig. 51. 





Fig. 50. 



Fig. 52. Fig. 53. 



Fig. 54. 




Fig. 55. 



Fig. 56. 



Fig. 57. 



SCRE^V PROPELLERS IVHEN SIVEPT UP IN LOAM. 65 




Fig. 58. 



Fig. 59. 




Fig. 60. 



Fig. 61. 



66 THE y4RT OF PATTERN-MAKING. 

used. At each division on the sweep a small notch 
is cut in the working edge; these notches leave a 
marked line on the face of the pier, by which the 
thickness pieces are set. 

The sweep Fig. 54 forms an elevation, or seat, 
on which the hub rests, and also a depression at 
the outer end, on which the guide sets. After the 
seat has been dried it is lined off according to the 
number of blades required. The sweep Fig. 55 
forms the pattern for the hub, which is usually 
built of brickwork and covered with loam, and 
shaped by revolving the sweep around it. The 
guide is next set in its proper position, and weighted 
to prevent its moving. The sweep Fig. 56, for the 
face of the pier on which the blade pattern is built, 
is now placed on the spindle and counterpoised, as 
illustrated at Fig. 60, to permit of its free move- 
ment up and down the spindle. The arrangements 
are now complete for the building of the pier to be 
commenced. 

It is necessary that the sweep Fig. 56 should 
move by the hub to a small distance below the 
lower edge of the blade. The sweep is thus left 
at this part without support, and it will invariably 
spring and finally cause the face of the pier to become 
somewhat distorted near the hub. To remedy this 
it was the practice of the writer to provide guides 
at the hub as well as at the periphery. These are 
shown at Fig. 57. If the screw is a small one, a 
half-hub, with the guide cut in it, may be used and 
shifted around for the several blades. If the screw 



SCREIV PROPELLERS IVHEN SIVEPT UP IN LOAM. 67 

is a large one, a framework of wood, having as 
many cylindrical faces as there are blades, is pro- 
vided. It is made somewhat less in diameter than 
the least diameter of the hub. A curfed strip is 
nailed on each of the cylindrical faces at the required 
angle according to the radius adopted, and these 
form the guides for the inner end of the sweep Fig. 
56. When this arrangement is used nails are 
driven into the cylindrical faces, to hold the loam 
with which it is covered; it is reduced to size and 
shape by a hub sweep. When sufficiently dry the 
loam is cut away to expose the guides. 

Fig. 58 shows the seat completed; Fig. 59, the 
hub swept up and the guide set. Fig. 60 illustrates 
two piers completed and one in course of building. 
At Fig. 61, a illustrates one pier as lined off with 
the thickness pieces in position. Another pier, h, 
is shown with -the pattern of the blade formed by 
filling in sand between the thickness pieces and 
dressing it off to the shape of the blade. The 
other pier, c, shows the cope, or upper part of the 
mould, which covers the blade completed upon it. 
After the copes are all completed the mould is 
taken apart and stripped of the patterns of the hub 
and blades. 

When a sweep at one end follows the axis and 
the other end the guide, the pitch will be uniform 
radially. It is sometimes desired to have the pitch 
variable in a radial direction, or a less pitch at the 
axis than at the periphery. In such a case the 
sweep is required to travel with a lower axial veloc- 



68 THE ART OF PATTERN-MAKING. 

ity at the hub than at the periphery. At Fig. 62 
a device is shown by which this can be accomphshed. 
The proper guides are provided at the hub and 
periphery. Two arms, each having a hole in its end, 
are secured to a spindle, which is free to turn with 
the arms. A rod is made to slide freely up and 
down through the holes in the arms. The sweep 
is pivoted to the lower end of the rod, and its ends 
made to bear on the two guides. The height of the 
blade at the hub and at the periphery being deter- 
mined, with a proper allowance for the guide being 
beyond the periphery of the blade, the distance on 
each guide is divided into the same number of equal 
parts. Consequently the vertical distance of a 
space on the hub guide will be less than one on the 
peripheral guide. The sweep is then made to travel 
through a space on the hub guide and a space on 
the peripheral guide in the same time. The other 
arrangements necessary to complete the mould 
are similar to those previously described. 

The foregoing is descriptive of the method of 
preparing moulds for propellers where the thick- 
ness of the blade is all on one side of a radial line. 
In some cases the thickness is given on both sides 
of a radial line equally, similar to a V thread; in 
other cases the thickness is unequally divided by 
such a line. 

When the thickness of the blade is all on one side 
of a radial line, the generatrix is the line exposed 
by a plane cutting the screw parallel with and pass- 
ing through the axis. The plane of the sweep 



SCREW PROPELLERS IVHEN SPVEPT UP IN LOAM. 69 




Fig. 62. 




Fig. 63. 



Fig. 64. 



Fig. 65. 



7o THE ART OF PATTERN-MAKING. 

must lie in the same plane as that cutting the 
screw. 

It is possible to generate the face of a screw by 
the line exposed by a plane cutting the screw per- 
pendicularly to the axis, the sweep lying in the 
same plane; but the vertical plane for the sweep 
is preferable. 

When the thickness of the blade is divided by a 
radial line, the generatrix is the line exposed by a 
plane cutting the screw parallel with but passing 
outside of the axis, the degree of obliquity depend- 
ing on the way in which the thickness is divided. 

When the generating line is not a right line per- 
pendicular to the axis of the screw, but a line of 
unusual form, occupying some peculiar position 
with reference to the axis of the screw, it becomes 
quite a difficult problem to work out the line on 
paper. The writer has found it convenient to work 
this out, as well as many other tedious problems, 
to a scale on white-pine blocks, and then develop 
the line from the one resulting. 

What is meant by the thickness being on one 
side of a radial line is shown by Fig. 63, where the 
thicknesses are exaggerated. Fig. 63 is a plan 
view, and a a section, of such a blade. Fig. 64 is a 
plan view of a blade where the thickness is on both 
sides of a radial line, the face of the blade being flat 
or straight; h is the section of the blade. Fig. 65 
is a plan view of a blade where the thickness is also 
on both sides of a radial line, but the face and back 



SCREIV PROPELLERS IVHEN SIVEPT UP IN LOAM, n 

of the blade are convex alike; c is a section of the 
blade. 

When the thickness of the blade is on both sides 
of a radial line and the face of the blade is flat, as 
shown at Figs. 63 and 64, either of the devices shown 
for sweeping up propellers can be employed, pro- 
vided the pitch is uniform radially; but when the 
section of the blade is like that of Fig. 65, or when the 
pitch is not uniform radially, the device shown at Fig. 
62 is alone applicable. With this device the sweep 
is fixed at right angles to the rod when the pitch is 
uniform radially, and pivoted thereto when the 
pitch is not imiform. W^hen the latter device is 
used, and the face of the blade is convex, the gui'de 
at the hub is so shaped as to produce the required 
convexity. 

Figs. 66 to 69 show a working drawing of a 
two-bladed screw propeller. The arcs a, h, c, d 
on the plan view are intended to represent sections 
of the blade at these points. These arcs are devel- 
oped into straight lines as shown, and are then 
projected to furnish the basis of the angles A, B, C, 
and D. The length of the blade measured axially 
being determined, it is laid off at one end of these 
base lines and perpendicular to them, the triangles 
being completed by a hypotenuse drawn between 
the extremities of each of the base and perpendic- 
ular lines. This hypotenuse is the length of the 
section of the blade developed. The greatest thick- 
ness of the blade at each of these sections being 
determined, it is laid off in the center of the hypote- 



72 THE ART OF PATTERN-MAKING. 

Fig. 69. Fig. 68. 



GUIDE 




Fig. 67. 



SCREfV PROPELLERS JVHEN SIVEPT UP IN LOAM. 73 

nuse, and an arc of a circle described through the 
extremity of this thickness dimension and tangent 
to arcs of one-half inch radius at the ends of the 
hypotenuse incloses the developed area of the 
section of the blade it represents. 

These sections furnish the forms and dimen- 
sions of the thickness pieces. These are made of 
pine board about three fourths of an inch thick. 
Fig. 66 shows a thickness piece which has been 
curfed with a saw, in order that it may be bent to 
the required curvature, the curfs being made par- 
allel with the axis of the screw. Fig. 67 shows the 
angle of the guide, whose base is also the length 
of its arc developed. 

The full hypotenuse line, which is a straight 
one, is the developed guide line for a true screw, 
and the dotted line is the guide for a screw of ex- 
panding pitch. Fig. 68 is a side elevation of the 
screw, and Fig. 69 is a scale of thickness through 
the thickest part of the blade. The sections repre- 
sented should always be given on a working draw- 
ing. 

When the screw is of expanding pitch, the lengths 
of at least five ordinates for the curvature of the 
guide line should be given. 



X. 

PATTERN WORK FOR RIFLE-PROJECTILES. 

Dry-sand moulding is adopted chiefly for large 
and intricate castings requiring solidity and accu- 
racy of form. It is a somewhat less expensive 
method of producing castings than by moulding 
in loam, especially when the castings are to be 
duplicated. Dry-sand moulds are made of spe- 
cially prepared sand, and are dried in an oven or 
a heated room; consequently metallic flasks be- 
come necessary. 

Patterns designed for moulding in dry sand do 
not materially differ from those intended for green 
sand. In some cases, however, they can be formed 
of fewer pieces, as cores and drawbacks are fre- 
quently made in the mould of the same material as 
the mould itself, and to better advantage than if 
made in separate boxes. 

Projectiles designed to carry explosives must be 
free from porosity to avoid the liability of the 
charge they contain becoming ignited by the firing 
of the gun, with the result of a premature explo- 
sion of the shell. When such projectiles are made 
of cast iron every precaution is taken to secure 
dense and accurate castings. The location of the 
core in reference to the exterior of a rifle-shell is 

74 



PATTERN IVORK FOR RIFLE-PROJECTILES, 75 

very important. Should there be eccentricity of 
the interior with the exterior, the flight of the pro- 
jectile is effected and the accuracy of aim is 
destroyed. 

Figs. 70 and 71 show a 13 -inch rifle-shell. Fig. 70 
is the pattern and Fig. 7 1 the core-box. The pattern 
is made solid, preferably of baywood. When large, 
as in the present case, two- or three-inch lumber is 
glued up imtil the desired size is obtained. A bar 
of ij-inch round iron, provided with a collar, is 
fitted through the center of the block and screwed 
half-way into a nut let into one end of the block, and 
the collar on the bar is let into the opposite end of 
the block. The remainder of the thread in the nut 
is for the double purpose of securing an eye-bolt 
when the pattern is to be withdrawn from the 
mould, and also to secure a center when the block 
is to be placed in the lathe. The end of the bar 
projecting outside the pattern contains a center, 
and the pattern is swung between those centers 
while being turned. The projecting bar, or center 
pin, is also turned so as to be concentric with the 
pattern. The pattern which is shown in the flask, 
with the position of the core dotted, is moulded in 
the position shown, and the draft or taper is toward 
the point of the shell. A cylindrical projection is 
made at the point of the shell to provide a sinking 
head. 

The core-box is made in sections as illustrated, 
segments of baywood being glued and nailed in 
the usual manner to form them. The sections are 



76 



THE ART OF PATTERN-MAKING. 







Fig. 71. 



Fig. 70. 



PATTERN IVORK FOR RIFLE-PROJECTILES, 77 

made to match by turning a projection on one end 
of a section and a corresponding recess on the end 
of the adjoining section. The core being tapered 
allows the sections to be drawn from the core in an 
axial direction. 

The first or lower section of the core-box is fitted 
with a sleeve, which is for the purpose of holding 
the vent-tube concentric with the core. The vent- 
tube performs two functions, that of carrying off 
the gases from the core, and supporting the core in 
position in the mould. That part of the vent-tube 
covered by the core is perforated with numerous 
holes, and small pine sticks are placed in these 
holes to assist in venting the core as well as to help 
secure it to the tube. The shells are moulded in 
a vertical position in special brass flasks, made in 
sections to facilitate ramming up. The first section 
of the flask has a cross-bar with a boss in the center 
of the flask; a hole through this boss corresponds 
with the diameter of the bar projecting from the 
pattern, also with that of the vent-tube projecting 
from the core. By this means, when the vent-tube 
is secured in the hole, the core is brought concentric 
with the mould. The core is set while the mould 
remains as when the pattern was drawn. After 
the core is set the mould is inverted and the shell 
cast with its point uppermost. 



XI. 
PATTERN FOR LAUNCH-ENGINE. 

Figs. 72-86 represent the pattern for an 8X8 
launch-engine. The cyHnder, valve-chest, frame, 
and bed-plate are combined in one casting. 

Fig. 72 shows a plan, Fig. 73 a front elevation, 
and Fig. 74 a side elevation of the pattern. Fig. 75 
shows a section of the cylinder through the steam- 
and exhaust-passages. The pattern is arranged 
for moulding with the valve-chest down, or in the 
drag, and is made to part through the axis of the 
cylinder. 

In making the pattern of the cylinder it is pref- 
erable to use well-seasoned lumber of thickness 
sufficient to allow of its being turned to the required 
dimensions without the gluing together of several 
pieces. To do this, lumber some five inches thick 
is required. In turning the cylinder, scores of about 
one quarter inch deep are made where the flanges 
are located; the latter are sawed out and fitted 
into these scores, being there glued and nailed and 
finished with the remainder of the cylinder. 

The open or top end of the cylinder has a core- 
print turned there. In length it is about equal to 
that part of the core which enters the cylinder in 
order to obtain sufficient support for the core, as 

78 



PATTERN FOR LAUNCH-ENGINE. 



79 




a 



Fig. 75. 




Fig. 76. 



o o 



M 



Fig. 77. 



Fig. 82. 



" R^ 




ii^ri 




Fig. 78. 



Fig. 79. 



I I- 



Fig. 83. 



4^ 




Fig. 80. 

I 

Fig. 81. 



^ 



Fig. 84. 



Fig. 85 



m 

Fig. 86. 



So THE ART OF PATTERN-MAKING. 

little can be had from the opposite or stuffing-box 
end, in consequence of the small diameter of the 
core there. 

The lower end of the cylinder has a cavity or 
recess turned in it, into which the pattern of the 
stuffing-box is fitted. The stuffing-box with its 
attached core-print, like the body of the cylinder, 
is made in halves and attached to the latter by 
dovetails in such a manner that it can be lifted out 
with the main core without affecting the cylinder. 

The main core is that which is formed below the 
cylinder and between the framing or housing and 
bed-plate. As commonly said, the pattern leaves 
its own core in that part. 

The bed-plate is made by framing together four 
pieces of the required thickness, of width sufficient 
to allow the plate to be reduced to the required 
shape. After the plate is worked to shape and 
lined off, the bearings for the shaft are added, and 
also the ribs or flanges which project below the 
plate. It is then sawed through the center of the 
bearings with a thin saw and the two halves dowelled 
to make it part in the same plane as that of the 
cylinder. 

The framing consists of conical-shaped frames, 
placed opposite each other, and which connect the 
bed-plate with the cylinder. Each is made in two 
pieces which part in the same plane as that of the 
cylinder and bed-plate, viz., on the line ah. In 
fitting the framing to connect the cylinder with the 
bed-plate, a surface board is first prepared and 



PATTERN FOR LAUNCH-ENGINE. 8i 

lined off. The dowel or drag halves of the cylinder 
and bed-plate are secured to this board in their 
correct relative positions. 

The drag halves of the frames are let into the 
cylinder about one and a half inches and secured 
there with glue and screws. At the opposite ends 
the frames are fitted against the bed-plate and 
glued to it; screws are also driven from the under 
side of the bed-plate into the ends of the frame. A 
large fillet is glued and nailed around the frame 
and to the bed-plate, and this aids materially in 
making the pattern more rigid at that part. 

The drag halves of the cylinder and bed-plate 
being secured to the framing, the pattern is released 
from the board and turned over; the cope halves 
of the cylinder and bed-plate are placed upon their 
drag halves, the cope framing being secured to them 
in a similar manner to that adopted with the drag. 

The valve-chest is fitted and secured to the drag 
half of the cylinder, the flange is fitted to the chest 
with steady-pins, but separates from it in the 
mould where a parting is made to enable the flange 
to be withdrawn. 

Figs. 76 and 77, respectively, show an end view 
and an elevation of one half of the core-box for the 
cylinder. 

Figs. 78 and 79 show a plan and a section of the 
core-box for the valve-chest. 

Figs. 80, 81, and 82 show a plan, a section, and 
an end elevation of the core-box for the steam- 
passages. 



82 THE ART OF PATTERN-M/iKING. 

Figs. 83, 84, 85, and 86 show a plan, an end eleva- 
tion, and a longitudinal and transverse section of 
the core-box for the exhaust-passage. 

In moulding the pattern, which is done in an 
iron flask, the drag part is laid upon a follow-board, 
and a box representing one half the main core is 
put between the frame to form the parting there. 
The mould is rammed up to the face of the valve- 
chest flange, a core is placed over the flange to cover 
it, and the mould is then continued until it sur- 
rounds the core. The latter is then removed and 
the pattern of the flange taken out, after which the 
core is replaced and the ramming of the drag com- 
pleted. The flask being turned over, the box repre- 
senting the main core is removed and a lifting-plate 
for the core is placed in the bottom of the space it 
formerly occupied. The main core is built upon 
the plate up to the parting. The cope half of the 
pattern is now placed in position and the main 
core is continued to completion. The cope of the 
mould is next completed and removed with the 
cope part of the pattern, leaving the stufling-box 
in the main core. The latter is now lifted out and 
the stufling-box removed from it. The main core 
being out of the way, the drag half of the pattern is 
withdrawn from the mould. 

More than one hundred castings have been made 
from a single pattern of baywood as thus described. 



XII. 

PATTERNS OF DECK-LUG FOR DRY-SAND 

MOULDING. 

In constructing large patterns to be moulded in 
dry sand it is frequently advantageous to arrange 
them for moulding somewhat after the manner of 
constructing loam moulds ; that is, to permit of the 
mould being made in sections which can be lifted 
away from the seat or foundation of the mould. 
The main core can then be made and finished on 
the seat and be allowed to remain there. The 
sides of the mould, which are sometimes called 
cheeks, are assembled around the core. This plan 
obviates handling the core, which may be large or 
of such a shape as to make the safe handling of it 
very difficult. 

Figs. 87-94 represent such an object, which is 
a deck-lug for a gun-mount. Three views of the 
casting are given — apian (Fig. 87), a side (Fig. 88), 
and an end elevation (Fig. 89). 

The pattern is moulded with the bearing down- 
ward. The ribs, flanges, and other parts pro- 
jecting from the sides are arranged to be removed 
with the cheeks. Fig. 88 also answers for the side 
view of the pattern when completed. The dotted 

83 



84 



THE ART OF PATTERN-MAKING. 



:h 



gSA^ J 



THEHHF 



i'^r ^ 




Fig. 87. 





Fig. 90. 



_1J II li IJ — -IJ- 



FiG. 89. 




Fig. 92. 




Fig. 93. 



Fig. 91. 



Fig. 94 



DECK-LUG FOR DRY-SAND MOULDING. 85 

lines outside the inclined ends represent the core- 
prints for the main core. The pattern separates 
or parts on the line ah. 

In constructing the pattern a number of frames 
made of 2 -inch lumber are first provided. These 
frames should be about if inches less all round 
than the section of the pattern where the frames 
are located. The frames are set up and properly 
arranged according to the position they are to occupy 
in the pattern; they are then covered with boards 
a little in excess of if inches thick; these are se- 
cured to the frames with screws and glue, the holes 
for the screw-heads being counterbored and plugged 
after the screws are in. 

■ When the box so formed is dressed down to the 
proper dimensions it forms the body of the pattern 
upon which the outside ribs, bosses, flanges, and other 
projecting parts are secured. This is done with 
draw-pins, screws being also used to insure the 
parts against shifting until the pattern is set up 
for moulding. The draw-pins are removed as the 
mould is being built up. 

Shallow core-prints are fitted to the two inclined 
sides of the pattern for the purpose of locating the 
core-box when placed upon the seat of the mould. 
The upper or cope part of the pattern, e, is con- 
structed in a manner similar to that described in 
the foregoing. 

Three views are given of the main core-box, Fig. 
90 being a longitudinal section. The plan, Fig. 91, 
not being correct to scale in width, is shown broken 



36 THE ART OF PATTERN-MAKING. 

through the middle. Fig. 92 represents a half 
cross-section of the box. 

The main core-box is constructed by first pre- 
paring a bottom board, which is secured to frames 
having the angles of the pattern where the core- 
prints are located. The sides and ends of the core- 
box are erected upon the bottom and are screwed 
together so that they can either be taken apart or 
removed from the bottom without being taken 
apart. 

The bottom board of the main core-box is not 
essential, absolutely, when the core is made in the 
place it is to occupy in the mould, as here intended. 
But by having it the box is better retained in shape, 
and, if so desired, the core can be made and set in 
the mould afterwards, as commonly done. 

Fig. 93 shows the box for the trunnion-bearing 
cores, and Fig. 94 the box in which the cores are 
made for the cope part of the pattern. These are 
plain boxes and require no further description. 

In moulding the pattern there is first prepared a 
seat or foundation corresponding in shape to the 
part of the pattern where the core-prints are located, 
and the pattern is placed upon this seat. The 
sides or cheeks of the mould are then built up and 
arranged to be lifted away from the mould without 
affecting the seat. The ribs, flanges, etc., on the 
sides of the pattern are lifted away with the cheeks, 
the pins and screws which secured them to the 
sides of the pattern having been withdrawn when 
the cheeks were being built up. The cope, or cover, 



DECK-LUG FOR DRY-SAND MOULDING. §7 

of the mould is also completed before the mould is 
taken apart. 

After the cheeks are removed the main core-box 
is lifted from its bottom and placed upon the seat 
of the mould, according to the position marked by 
the core-prints; the core is then completed and 
allowed to remain on the seat. When the mould is 
being assembled the rectangular cores are sup- 
ported on chaplets placed upon the main core. 



XIII. 

PATTERN WORK FOR WATER-COLLAR. 

Figs. 95-104 represent a water-collar and the 
pattern work for it. 

Water-collars are used in connection with the gun- 
turrets of war-ships, and consist of two principal 
parts; one of these is fixed and the other revolves 
with the turret. Water, under pressure, passes 
into the collar through a branch in the outer mem- 
ber, thence to a central passage in the inner member, 
and through it to the motors in the turret. The 
exhaust-water returns by another pipe, through 
an annular passage in the inner member, and thence 
through an outlet branch in the outer member. 
These castings are quite intricate; their patterns 
are interesting examples of pattern work, and con- 
siderable skill is required in their construction. 

Fig. 95 shows a side elevation and Fig. 96 a 
section of the device when assembled. The glands 
used for making the collar water-tight being ordi- 
nary glands, they are omitted. 

Fig. 97 shows a plan and Fig. 98 a side elevation 
of the pattern for the inner member; it is made in 
halves, the pattern parting on the line ab. The 
core-prints c, d form bearings to support the central 
core, and the prints e, /, bearings for supporting the 
annular core. Fig. 99 shows one half the box in 
which the central core is made. The annular core 

88 



PATTERN PVORK FOR HEATER-COLLAR. 89 

is made in halves. Fig. 100 shows a plan and sec- 
tion of the box in which the half-cores are made. 
These cores cut through the outside of the casting 
at g, h, where prints are located on the pattern to 
assist in supporting them in the mould, as well as to 
aid the venting. The holes so made are plugged in 
finishing the casting. 

In making the box for the annular core a bottom 
board of sufficient size, and which should be battened 
to prevent warping, is first prepared. Upon this 
board is fitted the body y, representing the outside 
of the metal inclosing the central passage. Two 
pieces, one right- and one left-hand, shown by dotted 
lines, are made for the upper end of this part where 
the bend is located. By interchanging these pieces 
both halves of the core can be made from the same 
box. To form the outside of the core, two pieces, x, 
one right- and one left-hand, are worked out on the 
inside to the outside form of the core over the bend ; 
an opening, e, is cut through one side of the pieces 
to form the outlet opening in the side of the casting, 
where the core-print, e, is located. By interchang- 
ing these pieces to correspond with the bend the 
opening is made to match when the halves of the 
core are set in the mould. Fitted to the opposite 
end of the box is a piece, n, worked out to form that 
part of the core which lays in the impression made 
by the print /. The strike, i, is for the purpose of 
shaping the part of the core between the two end 
pieces. 

After this part of the core is struck off, the piece k^ 



90 



THE ART OF PATTERN-MAKING. 




Fig. 96. 





Fig. 95. 



Fig. 97. 





1 -v 

° 1 

t \ 

-L 


! - 

1 





^o^ 


ko 





y 





L-u [ 


— ' n 



X 



p' 


_/ 


■r 


f^ 




fm 


I 





\\ 


' >^ 


^v 


:=ES: 




^-^ - " 




•^^ 



Fig. too. 



PATTERN IVORK FOR IVATER-COLLAR. 91 




\>y<'-^' 



W. 




Fig. 99. 




Fig. ioi. 



Fig. 102. 




■■ 






^ 



Fig. 103. 



Fig. 104. 



92 THE ART OF PATTERN-MAKING. 

which has dowel-pins to fit holes provided to locate 
its position on the board, is placed over the core 
and the small branches g and h are added to the 
main part by extending the core through the hole 
in piece k. The square hole or socket in the upper 
end of the casting is formed by an ordinary square 
core. 

Fig. loi shows a side elevation and Fig. 102 an 
end elevation of the pattern for the outer member, 
which has two supporting brackets attached. The 
pattern is in halves, and is made to part on the line 
Im. The spandrel between the brackets is formed 
by two similar cores, one of which is secured in the 
drag, and the other in the cope part of the mould. 
The core-prints 0, p form the bearings for support- 
ing these cores, which contain a bearing for the upper 
end of the interior core. When the mould is closed 
the cores meet at the joint of the mould. One ele- 
vation, r, and two sections, 5 and t, of the box in 
which these cores are made are also shown. 

Fig. 103 shows an end elevation of the box in 
which the interior core is made. 

Fig. 104 shows one half the box viewed from the 
interior. The box is built up of several pieces, as 
the illustration indicates; this facilitates working 
out the different diameters contained in the box. 
After being worked out the several pieces are assem- 
bled and secured together. 

The core is supported in the mould by the bear- 
ings made by the core-prints u, v, and w, and by the 
bearing in the cores between the brackets. 



XIV. 

PATTERN WORK FOR HIGH-PRESSURE 
CYLINDER FOR MARINE ENGINE. 

Figs. 105-117 represent a more intricate casting 
made in a dry-sand mould. It shows the high- 
pressure cyHnder of a compound engine having a 
valve-chest and a receiver combined with the cylin- 
der. Fig. 105 is a half plan and half cross-section 
and Fig. 106 is a vertical section through the axes 
of the cylinder and valve-chest. 

Prior to commencing the construction of such a 
pattern its position and the method of moulding 
must be decided. Having chosen a horizontal 
position, the pattern will be made to part or separate 
through the axes of the cylinder and valve-chest on 
the line ab. 

Four frames of 2 -inch lumber are prepared. 
These frames extend beyond the cylinder proper, or 
casting, and the core-print for the receiver core is 
formed on this extension. Each frame is made in 
two pieces, the joint running through the axes of 
the cylinder and valve-chest. The contour of each 
frame is less by about ij inches than the exterior 
of the finished pattern. The finished exterior is 
illustrated in Fig. 107. 

A frame is placed at each end of the pattern, the 

93 



94 THE ART OF PATTERN-MAKING. 

other two being set intermediate and equidistant 
between the end ones, as shown at Fig. io8. The 
frames are covered on their outer edges with staves 
running parallel with the axis of the cylinder, as 
shown in Fig. 109. The staves are made of 2 -inch 
lumber, and are secured to the frames with screws 
and glue. After dressing the ends of the staves 
fair with the frames, the pattern is lined off, and 
finished to this line by removing the surplus material 
with planes. The screws having been countersunk, 
to avoid coming in contact with the tools, the screw- 
holes are filled by plugs. 

The lower head of the cylinder is cast in ; that is, 
it is made a part of the casting. To form this head 
in the mould a piece is built up of segments, and 
turned to the required shape and dimensions. The 
frame at the proper end of the cylinder is cut away 
sufficiently to allow the insertion of the turned 
piece, which is secured to the pattern, as shown in 
Fig. 108, where is also shown a section of the pattern 
through the axes of the cylinder and valve-chest. 
The piece forming the nozzle with core-print at- 
tached is fitted to the head, and is made to lift out 
of it when the mould is being separated. This 
relieves that portion of the mould forming the 
head, which parts as does the pattern and allows of 
removal from the flask after the mould is opened. 
When this part of the mould, or drawback as it is 
sometimes called, is removed, the pattern is free 
for withdrawal from the mould. 

The part of the pattern that forms the valve-chest 



CYLINDER FOR MARINE ENGINE. 95 

is made in halves, with a core-print at each end. It 
is built up of staves, in a manner similar to that of 
the body of the cylinder, and, being of moderate size, 
is turned to the proper shape and dimensions in a 
lathe. The valve-chest is secured to the other 
part of the pattern with screws and glue. The 
projections on the valve-chest that form the outer 
walls of the steam-passages are next fitted, after 
which the part containing the induction-passage 
and nozzle is fitted and secured to the valve-chest. 
This piece is made to part like the other portion of 
the pattern, and is worked out of solid material, 
the core-print and flange being turned and added 
to it. 

The top and bottom flanges, which extend all 
around the ends of the cylinder and valve-chest, 
are next added, after which the brackets by which 
the casting is secured to the engine framing are 
added; also the bosses for the relief- valves and 
facings for the hand-holes, etc., are fitted. The 
core-print for the upper or open end of the cylinder 
is built up of segments and turned to dimensions. 
It is secured to the end of the cylinder with screws 
and glue. 

The pattern is now ready to be cleaned off and 
to receive its coat of shellac. The completed pat- 
tern is shown in Fig. 107. 

A plan and a sectional view of the core-box for 
the receiver core are shown respectively in Fig. no 
and Fig. in. It is a half-box, the one box an- 
swering for both halves by having right and left 



96 



THE ART OF PATTERN-MAKING. 



pieces, c, d, which are secured in the box according 
to the half of core to be made. 




Fig. 114. Fig. 115. Fig. 116. Fig. 117. 




Fig. 106. 



Fig. 107. 



The box is constructed by first preparing a bottom 
board, then fitting together the sides and mounting 



CYLINDER FOR MARINE ENGINE. 

a 



97 




Fig. 112. 



^8 THE ART OF PATTERN-MAKING. 

them on the board. The half-cylinder which forms 
the inner wall of the receiver is constructed by 
preparing heads and securing staves to them, which, 
when worked off, will produce the required cylin- 
drical dimensions. The upper edges of the sides are 
worked to the outer shape of the core, a straight- 
edge being used to sweep off the core to the form 
of the sides of the box. 

Each half-core is supported in the mould at the 
open end of the receiver, at two places on the cylin- 
der, /, /, and at one on the valve-chest, m, where the 
cylindrical openings cut through the outer wall of 
the casting. The corresponding letters on the core- 
box show where the core is extended for this pur- 
pose. The openings are plugged up in course of 
finishing the casting. 

Fig. 112 illustrates the core-box for the induction- 
passage to the valve-chest. The view shows the 
inside of one half the box when separated. Fig. 113 
shows a section through both halves of the box. 
This core is made in halves, the parting being on 
the line ef, and it is supported in the mould at 
the three ends where core-prints have left im- 
pressions. A cylindrical opening is made through 
the core for the purpose of providing support for 
the cores for the steam-passages to the cylinder. 

Fig. 114 represents one half the box in which 
the cores for the steam-passages are made ; the box' 
is made to part or separate on the line hi. Two 
of these cores are necessary, differing in length 
where they pass through the induction-core. One 



CYLINDER FOR MARINE ENGINE. 99 

core is made with the piece g attached to the box, 
and one, Fig. 115, for the upper passage without 
it. The box is made open on the upper side, k, to 
facihtate ramming the core up. These cores are 
supported in the mould on one side by the induc- 
tion-passage core, which they pass through, and on 
the other side by the exhaust end of the receiver 
core. It is necessary to support them also by 
chaplets. 

Fig. 117 illustrates the core-box for the interior 
of the cylinder. Two views are shown, a plan and 
an end view. For that part of the core containing 
its large diameter a half-box for the lower half of 
the core is sufficient, the upper half of the core 
being formed by a strike, /, which is shown in the 
position in which it is used. It is advisable to 
make both halves for the other end of the box, which 
contains the smaller diameter. 

The part projecting inwardly, marked m, is made 
to lift out with the core when it is taken from the 
box, and is withdrawn from the core afterwards. 
This core can also be made by turning it up on a 
core-barrel ; but if this has to be specially made, it 
will be more economical to dispense with it and 
make a box like that described above. 

L.ofC. 



XV. 

PATTERN FOR A GUN-MOUNT PEDESTAL. 

Figs, i 18-12 5 represent a pattern for the pedestal 
of a gun-mount. It consists of a socket combined 
with a flanged housing, by which it is secured to 
the deck of the vessel. 

The top carriage, on which the gun is mounted, 
has a pivot on its lower side, and when the pivot 
rests in the socket of the pedestal the top carriage 
can be revolved in a horizontal plane. 

Pedestals are subjected to very heavy strains, 
and their construction consequently must be relia- 
ble and solid. 

Fig. 118 is a plan view. Fig. 119 a side elevation, 
Fig. 120 a longitudinal and Fig. 121 a transverse 
section of the pattern. 

The flange, a, and the central body, or boss, for 
the socket, b, are the pieces first required when 
beginning the construction of the pattern. The 
former is built up with two courses of segments 
glued and screwed together. The latter, which is 
turned, is preferably made of thick material in order 
to have as few glue- joints as possible. 

These pieces being prepared, the flange is secured 

to a surface board and the center piece, b, set up and 

100 



PATTERN FOR A GUhl-MOUNT PEDESTAL. 



lOI 



secured in its proper position relatively to the flange. 
The housing, c, which surrounds the central boss 




Fig. 1 20. 



Fig. 121. 






rrtr-?^-><% 



Fig. 124. 



If 






Fig 122. 



Fig, 123. 



Fig. 125. 



is then fitted to the flange at the bottom and to the 
boss at the top. The staves forming the housing 
are about four inches wide at their bottom ends. 



I02 THE ART OF PATTERN-MAKING. 

Considerable work is involved in fitting and shap- 
ing the staves conformably with the different posi- 
tions which they occupy in the housing. They are 
secured in place by glue and screws, nails also 
being used where necessary. When securing them 
in place three staves are closely joined and secured 
together, and then a joint is left open about one 
eighth of an inch. This is continued alternately 
around the pattern, to allow for the swelling of the 
wood while the pattern is being moulded, and has 
been found necessary in consequence of the great 
width made around the pattern by the staves. 

The openings in the sides of the housing for the 
purpose of allowing access to the interior of the 
pedestal are formed with cores. Fig. 124 shows 
an end view and Fig. 125 a section of the box in 
which these cores are made, d and d, Fig. 120, are 
the core-prints for the location and support of these 
cores. The central piece, h, Fig. 121, and also the 
ribs, e, which connect the former with the housing, 
are arranged to lift out with the main core. 

Fig. 122 shows an end view of the core-box for 
the socket, and Fig. 123 shows one half of the box 
as viewed from the inside. The prints for the sup- 
port of the core are shown in / and g. The flange, 
a, Fig. 118, is made in two parts; the part pro- 
jecting beneath the housing is made to separate 
from that outside of it, that it may be withdrawn 
from the mould independently of the remainder of 
the pattern. 

In moulding, the pattern is first inverted and 



PATTERN FOR A GUN-MOUNT PEDESTAL. 103 

the main core made inside. This completed, the 
part of the flange projecting inside the housing is 
removed and the position of the pattern with the 
core IS reversed. The mould is completed and the 
castmg made in this latter position. 



XVL 

PATTERN WORK FOR SCREW PROPELLER 
CAST ENTIRE. 

When screw propellers are of large size and cast 
entire they are usually swept up in loam, but 
when the blades are made separate and are to be 
bolted to the hub, or when the screw is to be dupli- 
cated, a pattern of the blade is usually made and 
the moulding done in dry sand. 

To construct the pattern of a screw-propeller 
blade attached to a hub is an interesting and in- 
structive example of pattern-making. Working 
drawings of screws are made in different ways, 
according to the ideas of the draughtsman; one 
way has been described. 

Figs. 1 2 6-1 3 1 show another method. Fig. 126 

represents a plan and Fig. 127 an elevation of a 

right screw with two of the four blades broken off. 

These views are often assumed by the draughtsman 

to be all that is necessary in order to enable the 

pattern-maker to proceed with the construction of 

the pattern; but the developed sections should be 

worked out by the draughtsman. When they are not 

so done the pattern-maker may develop them himself. 

In this event, after receiving the drawing, the first 

Z04 



SCREIV PROPELLER CAST ENTIRE. 105 

thing he should do is to lay down full-size developed 
sections of the blade. These are readily deter- 
mined in the following manner: Draw a line ah, 
Fig. 128, for a center line somewhat longer than the 
radius of the screw. With the radius of the screw 
and with one point of the trammel on the center line 
describe an arc equal in length to the fraction of 
the circumference occupied by one blade. Develop 
this arc into a right line at right angles to the center 
line, and from its extremities draw radii to the 
center from which the arc was described. Divide 
the center line into as many parts as it is desired 
to have sections of the blade (four are used in the 
illustration), and through the intersections draw 
lines at right angles to the center line and inter- 
secting the two outside radial lines; the length of 
the lines between these intersections are those of 
the bases of the triangles c, d, e, and /, or periphery. 
The triangles are completed. Fig. 128, by erecting a 
perpendicular from the end of each base line. The 
height of these perpendiculars should be equal to 
the length of the screw, measured parallel with its 
axis. Now join the top of the perpendicular with 
the opposite end of the base line by a straight line 
for a right screw, as that represented. 

For the purpose of laying down the thickness of 
blade at the different sections, as well as the parallel 
pieces with which the blade is built, it will be found 
convenient to arrange the triangles as shown in 
Fig. 129. 

From a scale of thickness as that shown in connec- 



to6 



THE ART OF PATTERN-MAKING. 




SCREIV PROPELLER CAST ENTIRE. 107 

tion with the plan view, Fig. 126, which shows 
the thickest part of the blade at right angles to 
the face, take the thickness of each section, 
as c, d, e, f, and also at the hub. Lay it off at 
right angles to the center of the hypotenuse 
of the triangle corresponding in section. From the 
ends of each hypotenuse describe an arc the radius 
of which is equal to that of the edge of the blade. 
For each section describe an arc of a circle inter- 
secting the arcs at the ends and the thickness dimen- 
sion in the center of the hypotenuse, and the area 
thus inclosed will be the section of the blade at that 
part. 

Now determine the thickness of the parallel 
pieces (Fig. 130), as i, 2, 3, 4, 5, and 6, to be em- 
ployed in constructing the pattern. This thick- 
ness may vary from if to if inches, according to 
the size of the blade. Draw lines through the sec- 
tions of blade parallel with each other and perpen- 
dicular to the axis of the screw, with a distance 
between them equal to the thickness of the material 
adopted. From each intersection of those par- 
allel lines with the lines bounding the sections of 
the blade through which they pass, other lines at 
right angles to them are drawn to the adjacent line, 
and thus a series of rectangles is produced which 
are the widths of the parallel pieces necessary to 
make the thickness at those parts. 

When the screw is a true or right one, as that 
under consideration, the face lines of these parallel 
pieces are right lines radiating from the center of 



io8 THE ART OF PATTERN-MAKING. 

the screw, because a right screw is generated by a 
right Hne perpendicular to the axis radiating from 
the center and having a uniform axial progress 
while revolving. But all screws are not so made. 
The generating line is made of various forms and is 
set at different positions with the axis. It is also 
given variable as well as uniform axial motion 
while revolving. Sometimes the generating line is 
given the form of an arc of a circle described from 
the rearward of the axial line. In such a case the 
face line of the parallel pieces will be a spiral of in- 
creasing curvature toward the periphery. Then, 
again, the generatrix may be made a right line 
radiating from the axis, but having a less axial 
motion at the axis than at the periphery, producing 
a screw of diminishing pitch toward the axis. In 
this latter case when the pattern is built up of pieces 
of parallel thickness only, the center line between 
the extremities of the pitches will be a right line per- 
pendicular to and radiating from the axis. With 
each succeeding piece forward of the center line 
the face line will increase in convexity, while for 
each succeeding piece aft of it the face line will 
increase in concavity and the face line would have 
to be worked out for each piece of parallel thick- 
ness. 

In a case of this kind the construction of the 
pattern will be made easier by making the pieces 
tapering instead of parallel in thickness, reducing 
the thickness of each piece at the axis in proportion 
to the difference in the pitches; and then the face 



SCREIV PROPELLER CAST ENTIRE. 109 

line of each piece would be a right line radiating 
from the axis. 

The drawing is made convenient for building the 
screw with the face upward, and some workmen 
prefer doing it in this way ; but the writer, who has 
had a very large experience in constructing patterns 
for screws, is decidedly in favor of making them face 
downward, as greater accuracy can be thereby 
attained. 

All the necessary preliminaries to laying off the 
different pieces being completed and the material 
with which the blade is to be constructed prepared, 
it is only necessary to transfer the dimensions found 
to the pieces. 

As the method is similar for all of the pieces, a de- 
scription of the preparation of one will answer for all : 

Select for No. i, or bottom, a piece not less in 
width than the widest section on that line. Make 
one edge of it straight and square with the sides, lay 
off on it the several radii, as c, d, e, f (Fig. 126), and 
also the radius of the hub on that line. Beginning 
either with the hub or the peripheral end, with a 
pair of dividers step off the width of the section and 
transfer it to the arc of corresponding radius on the 
piece. Proceed in a similar manner for each suc- 
ceeding section on that line. Tack a flexible batten 
on the piece with its edge passing through the inter- 
sections made on the arcs, draw a line along that 
edge, and work off the piece to that line square with 
its sides. 



no THE ART OF PATTERN-MAKING. 

Grouped in Fig. 130 are shown the different 
pieces shaped and ready for building the blade. 

A surface-board is necessary to insure satisfactory 
work. It should be lined off and the hub secured 
in its proper position upon it. The pieces are fitted 
against the hub. As the blade is to be made face 
upward, a guide secured at the periphery is neces- 
sary to insure the proper angle; props are also to 
be employed beneath the pattern to keep the pieces 
up to the guide, as there is a tendency of the pieces 
to depress on their overhanging side. Each piece, 
as the building up progresses, is set back on the 
piece below it and glued and nailed thereto, care 
being observed that the nails are out of the way of 
the tools in working the blade off. In the latter 
case it is only necessary to work down to the lines 
formed by the outside of the joints to obtain the 
required thickness throughout the blade. After 
the blade is worked off it can be made any desired 
shape within the limits of the pattern by laying off 
the outline and working off the surplus material, and 
easing off the back to suit the shape adopted. 

When the screw is not very large the hub may 
be formed at the same time that the blade is 
being built up by laying off a section of the hub 
and blade on the same piece, as shown shaded 
by g, Fig. 131. But when the screw is of large 
size, it is more convenient to turn the hub sepa- 
rately and fit the pieces to it while building the 
blade. 

Unless the screw is quite small, it is not necessary 



SCREIV PROPELLER. CAST ENTIRE, iii 

to make more of the pattern than one blade and 
the hub, as the pattern can be shifted around in 
moulding to make the required number of blades 
in the casting. 



XVII. 

METHOD OF MAKING A PATTERN FOR A 
SCREW PROPELLER WITH SEPARABLE 
BLADES. 

Figs. 132-135 show a screw propeller different in 
shape from the one previously described. The 
views are numbered to follow consecutively those 
that have already appeared. The screw is a true 
one, that is, its pitch is imiform both radially and 
axially. 

It will be observed that a blade developed on a 
plane is oval in shape, as shown in Fig. 132. The 
outer oval figure is intended to represent the shape 
of the blade as thus developed. Instead of the 
screw being cast entire the blades are made sepa- 
rately and provided with a flange for bolting them 
to the hub or boss. This is the type usually adopted 
for the propellers of ocean-going steamers. It pos- 
sesses a distinct advantage when in need of repairs, 
for a broken blade can be renewed without removal 
of the screw from the vessel. However, a propeller 
of this kind is more expensive in first cost. 

When a pattern is to be made of such a screw, and 

the drawing, as is generally the case, does not show 

112 



SCREJV PROPELLER JVITH SEP/4RABLE BLADES. 113 

the developed sections of the blade, these should 
be developed by the pattern-maker to full size. 
He should then determine the thickness of the 
material of which the blade is to be built and line 
off the sections with parallel lines according to the 
thickness adopted. It is well to dress up the lum- 
ber for the blade, rip it in pieces of sufficient size 
and allow it to stand until wanted for use. Next 
make two guide-frames, one to conform to the angle 
of the pitch at the hub and the other to the angle 
of the pitch at the periphery. As the blade pattern 
is to be made with the face downward, the angles 
of these guides will determine the proper helical 
form of the face of the blade. The method of making 
these guides has been explained. 

A substantial surface-board is required. It should 
be somewhat longer than the radius of the screw, 
and in width a little greater than the length of base 
of the largest guide. On this board draw a line 
through it lengthwise for a center line. With the 
radius of the screw and with one point of the trammel 
on the center line describe an arc across the board, 
the arc at the center line being about five inches 
from the end of the board. From the same center 
with a radius equal to that of the hub describe 
another arc across the board. Step off the length 
of the base of the triangle e, at Fig. 133, the periphery 
of which will be equal to the length of the base of the 
largest guide. Transfer this length to the arc corre- 
sponding on the surface -board, making it equal on 
each side of the center line. From the extremities of 



114 



THE ART OF PATTERN-MAKING. 




SCREIV PROPELLER WITH SEPARABLE BLADES. 115 

the arc draw radii to the center, and the sector thus 
formed will be that with which a plan view of the 
blade will agree when its top and bottom edges are 
perpendicular to the axis of the screw. 

To determine the necessary length of the base of the 
guide when the outline of the blade is of special shape 
like that under consideration, it is necessary to 
lay down a projected view of the blade as viewed 
in line with the axis of the screw. Radial lines 
are then drawn tangent to the edges of the blade 
as at /, Fig. 132. The length of the arc at the 
periphery intersecting these lines is the fraction of 
the circumference the blade extends through and 
it is also the length of the base of the guide. 

The two guides being prepared and having center 
lines drawn upon them, are to be secured to the sur- 
face-board, their center lines and curvatures coin- 
ciding with the arcs drawn on the board ; the guide 
on the periphery being on the inside of its arc. A 
pattern for the flange by which the blade is secured 
to the hub is required. It is to be secured to the 
surface-board by brackets, being properly situated 
in relation to the face of the blade as determined 
by the guides. 

To facilitate laying off the pieces for the blade 
a templet like that illustrated in Fig. 134 will be 
foimd useful. It is made of thin stuff equal in 
length to the radius of the screw. The arcs of the 
different sections, as a, h, c, d, and also those of 
the hub and periphery, are described upon it and 
enough of the templet cut away to admit of the 



Ii6 THE ART OF PATTERN-MAKING. 

arcs acting as guides while they are being marked 
on the blade pieces. The necessary preparations are 
now completed to allow the building of the blade to 
proceed. 

It is not absolutely necessary with a blade pat- 
tern of this shape, where so much of it is cut away 
toward the periphery, to continue every piece to 
the outside guide. But the writer has found it 
good practice to do so. The small amount of mate- 
rial saved by stopping some of the pieces at the top 
and bottom short of the outside guide does not 
compensate for the extra care it involves to insure 
accuracy. 

To begin the building of the blade pattern, select 
from the stuff previously prepared a piece of suffi- 
cient size to make the bottom piece marked i, 
straighten one edge and make it square with the 
sides. Fit the straight edge of the piece against the 
guides with its side lying on the surface-board by 
beveling the edge where it comes in contact with 
the guides, being careful to have the bevels ter- 
minate exactly at the upper edge of the piece where 
it touches the guides. If it should occur in fitting 
a piece that the top of the bevel is carried in beyond 
the edge, the edge can be planed off until it coincides 
with the bevel. In this lies one of the advantages 
of fitting the pieces to the guides before reducing 
them to the shape in which they are built into the 
pattern. 

Now mark the periphery of the blade on the 
piece which will be the outer edge of the outside 



SCREIV PROPELLER IVITH SEPARABLE BLADES, n? 

guide; also mark the radius of the hub, which is 
the inside edge of the inner guide. Lay the templet 
on the piece, the marks for hub and. periphery coin- 
ciding with those of the templet, and mark the arcs 
of the different radii a, h, c, d, etc. Take the widths 
of the piece i at the different sections and lay them 
off on the piece i. On the arcs corresponding to 
the section draw a line through these intersections 
with the aid of a batten, work off the edge to this 
line square with the sides, place the piece on the 
surface-board where it was fitted against the guides, 
securing it there against shifting, but in such a 
manner that it may be readily released when de- 
sired. Proceed in a similar manner with piece 
No. 2, which, when prepared, secure on the piece 
No. I by glue, and with nails where they are not 
likely to come in contact with the tools in working 
the blade off. The remainder of the blade is simi- 
larly proceeded r/ith until completed to the desired 
height. Where the parallel pieces come in contact 
with the flange they are fitting against it as well as 
against the guides. The shapes of the several pieces 
forming the blade are shown in Fig. 135. 

After the pattern has been completed to the 
required height and before it is removed from the 
guides, it is to be roughly worked off on the back. 
Large, inside bevel gouges are useful for this purpose. 
The pattern is then to be turned over, with the face 
upward, utilizing the guides to hold it while the 
face is being worked off. When the face of the 
pattern is finished down to the lines formed by the 



ii8 



THE ART OF PATTERN-MAKING. 



joints of the pieces, the configuration of the blade is 
the next thing in order. This can be laid off di- 
rectly on the face of the pattern, or a templet of 



<^^ 




Fig. 136. 




d 



Fig. 137. 



Fig. 138. 





Fig. 139. 







Fig. 140. 



Fig. 141. 



the shape can be made of stiff paper and the pattern 
marked by it. 

The shape of the blade being lined off on the face 



SCRE^V PROPELLER IVITH SEPARABLE BLADES. 119 

of the pattern, the surplus material outside of this 
boundary is to be removed. This accomplished, 
the face is given a coat or two of shellac and the 
pattern turned with its face downward and its back 
worked off down to the lines formed by the joints 
of the pieces of which the pattern is composed. 
The edges are next to be finished by working ofE 
the back to an easy curve where it trends toward 
the face. 

When building up the blade it is well to avoid 
gluing the flange to the blade pieces. By arranging 
the flange to be removed while the blade is being 
worked off the latter is accomplished much easier. 

After the flange has been secured permanently 
to the blade, the fillets where they join are com- 
pleted. The fillet on the back may be worked on the 
pieces which compose the blade, but the fillet on 
the face is best fitted separately. 

After being sandpapered and receiving several 
coats of shellac, the pattern is ready to be moulded. 

Glue alone should not be depended upon to hold 
the pattern together while being moulded. Brads 
should also be freely used for the purpose. 

Fig. 142 shows a partly built-up blade pattern. 
It differs in shape from those shown in the draw- 
ings. For the purpose of making prominent the 
manner in which the pieces of parallel thickness 
are fitted upon each other and to the guides they are 
shown somewhat disproportionate in thickness. 

Figs. 1 36-141 show the method of constructing 
the pattern for the hub, or, as it is termed in Eng- 



I20 



THE ART OF PATTERN-MAKING. 



land, the boss, which is generally moulded in loam 
when very large. When so moulded the pattern is 




made a model of the casting, but so constructed that 
It can be taken apart to permit of its withdrawal 
from the mould and the release of the interior parts 



SCREIV PROPELLER IVITH SEPARABLE BLADES. 121 

or cores which have been made in the course of 
moulding it. 

When the hub is of moderate size it is best moulded 
in dry sand. In this case it is first constructed in 
the form of a box which separates or parts diago- 
nally across its ends. To form the sides four 
frames, as in Fig. 136, are made of stuff sufficient in 
thickness to allow of their being worked to the 
required spherical form. Each frame is made of 
four pieces. When these are joined together, 
they leave an opening in the middle of the frame 
which is covered by the core-print for that core 
which forms the recess in the side. 

The frames are fitted together with miter- joints 
(see Fig. 137). They are secured in pairs, each pair be- 
ing glued and nailed together where they unite. The 
ends of the box, which are square in shape, are made 
in two pieces parting diagonally across the square. 
After these are secured to the sides corner blocks 
are glued and nailed inside the box to strengthen 
it at the comers where it is liable to be reduced to 
small thickness in being worked to the spherical form. 
Previous to securing the frames together their mi- 
tered ends are marked oft' by a templet having the 
radius of the hub, and the material outside of this 
line is worked off square with the joint. When the 
four frames are put together the outline of the miter 
joints gives the shape to which the pattern is to be 
worked in reducing it to the spherical form. The 
spherical form can be obtained either by turning 
in a lathe or by working the pattern off by hand. 



122 THE ART OF PATTERN-MAKING. 

The writer has employed both methods, but prefers 
the latter when the pattern is to be moulded in dry 
sand and cores are used to form the interior of the 
mould. 

After the spherical form has been given to the 
pattern it is ready for the core-prints. The prints 
a, h, Fig. 138, for the tapered core which forms the 
shaft-hole are secured permanently to the pattern; 
but c, d, e, f, on the sides, for the cores which form 
the recesses where the blades are secured to the 
hub, are made removable. They are held in place 
by draw-pins, which are withdrawn while the pat- 
tern is being moulded, thus releasing the prints 
from the pattern and allowing the latter to be 
drawn from the mould first and the prints after- 
wards. 

The recess cores are inserted from the inside of the 
mould previous to setting the main core, and are 
secured in the impressions made for them by the 
prints. 

Fig. 139 shows a longitudinal and transverse 
section of the box for the core which forms the hole 
for the shaft through the hub. When but one cast- 
ing is needed a half -box can be made to answer; 
but when several castings are required it pays to 
make a whole box. 

Fig. 140 shows a plan and a section of the box 
for the core which forms the recesses in the sides of 
the hub where the blades are bolted to it. Fig. 141 
shows a plan and a section of the box for the core 
which forms the recess in the flange of the blade. 



XVIII. 

CONSTRUCTION OF SMALL SCREW PRO- 
PELLERS. 

In constructing small screw propellers, unless 
special precautions are taken in view of the frailty 
of the pattern, much difficulty will be encountered in 
making it retain its shape while being moulded. 
In moulding a wooden pattern of this kind it be- 
comes necessary to provide a block or follow-board 
for the support of the pattern while the mould is 
being rammed up. This block is sometimes made 
of plaster of Paris, its form being obtained from 
the pattern itself. 

In an establishment where many patterns of 
small screws of various forms were made, and 
where different methods of making and moulding 
such screws were tried, that which insured the 
greatest satisfaction was first to make a block of 
wood whose helicoidal face represented the equiva- 
lent of the screw desired. Upon this block the pat- 
tern for the blade was built of alternate pieces of 
pine and baywood. The block was afterward em- 
ployed to support the pattern while being moulded. 
This method has special merit when the screw is 

123 



124 THE ART OF PATTERN-MAKING, 

of peculiar form and a correct casting is desired. By 
this method, also, the moulding is done with green 
sand in a core-box, a pattern of but one blade being 
necessary in order to obtain as many blades as may 
be required in the casting. It also insures the cast- 
ing of all blades as nearly alike as it is practically 
possible to make them, and secures uniformity 
throughout the casting — which is very important 
when experimental data are desired. 

Fig. 143 shows the first step of the process, namely, 
that of making the block. This is made of about 
2 J inches greater radius than that of the pattern to 
allow for the joint of the mould. It is not neces- 
sary to make the block of the full dimensions of the 
box, but merely of sufficient width and depth to 
admit a joint around the outside of the pattern of 
the blade. If the screw is to be a true or right one, 
as that illustrated, the block should be built up of 
pieces of equal thickness, the edges being straight 
and radiating from the center. Given the diameter 
and pitch of the screw, the first thing is to lay off a 
developed diagram of the periphery of the block, 
from which diagram are to be determined the thick- 
ness and width of the pieces that will constitute the 
block. 

Suppose a true screw, of four blades 30 inches 
in diameter and 45 inches pitch, is required. Add- 
ing 2^ inches to the radius for the joint of the mould 
will make the block 17 J inches radius. One fourth 
of the corresponding circumference will make the 
base of the triangle 27 J inches, and one fourth of the 



CONSTRUCTION OF SMALL SCREIV PROPELLERS, 125 

pitch will give an altitude of 11 J inches. Dividing 
this last by ten will give i \ inches, the thickness of 
the pieces. Dividing the base by the same num- 
ber gives 2f inches as the distance on the periphery 
that the edge of each piece must be set back of the 
piece below it when building up the block from the 
bottom. When preparing the pieces it is advisa- 
ble to make them somewhat wider than their finished 
widths, as by so doing the joints can be more easily 
made. The surplus material may be removed after 
the block has been worked off. 

In building the pattern of the blade it is advisa- 
ble to have the two outside edges of baywood. 
Beginning at the bottom, which will be the after 
edge of the blade, a piece of baywood is fitted to the 
block and. tacked thereto in its proper position. 
A piece of pine is next fitted to the block, and, to 
make a close joint with the baywood strip to which 
it is to be glued, this pine piece is also tacked to the 
block. The other pieces which go to form the blade 
are prepared in a similar manner. As each piece 
is fitted, the thickness of the blade at that part is 
laid off on it and the back of the piece is chamfered 
to the line. The thickness can be obtained by lay- 
ing down the sections of the blade as shown in Fig. 
152. In order not to have the pieces too thin (in 
which case it would be more difficult to make good 
joints) it is advisable to shape the pieces as shown 
in Fig. 152. In this sketch the lower parts of the 
sections of the blade are shown built up with pieces 
somewhat thicker than the finished dimensions, with 



126 



THE ART OF PATTERN-MAKING. 




Fig. 151. 








Fig. 152. 



CONSTRUCTION OF SMALL SCREIV PROPELLERS. 127 

one of their sides chamfered to the finished Hne. 
The upper parts of the sections are represented as 
when reduced to finished size. 

When all the pieces forming the blade are glued 
together and sufficiently dry, the pattern is removed 
from the block, its face smoothed, the outline of the 
blade laid off and the edges worked to the line. The 
back of the pattern is next worked off, and the 
whole then finished with shellac, when it is ready 
to be fitted to the hub. If preferred, the section 
of the hub can be fitted in its place on the block, 
and the pieces forming the blade fitted on at the 
same time that they are being fitted to the block. 
There is little choice, however, between the two 
methods. The blade is to be secured to the hub 
by glue and screws. Sufficient margin for the 
joints of the mould is to be laid off on the block 
outside the blade, and the surplus material of the 
block removed. The pattern will then be prepared 
for the core-box. This is made four or five inches 
deeper than the block and pattern, and should be 
made to be taken apart, as in Fig. 145. The angle 
of the core-box is made according to the number 
of blades required in the screw. For a three-bladed 
screw the box will extend through 120 degrees; 
for a four-bladed screw, through 90 degrees, etc. 
The box should be made of two-inch material, put 
together with screws, and the outside or circular end 
so arranged as to admit of easy removal. 

Before beginning the mould, it is necessary to 
provide a skeleton of cast iron for building in the 



128 THE ART OF PATTERN-MAKING. 

cores for the drag parts of the mould, and skeletons 
also for the copes; all these should be provided 
with suitable lifters. 

When beginning the mould, the block with the 
pattern being in the bottom of the box, the remain- 
der of the box is rammed up with green sand, 
the skeleton having been properly placed in the 
mould during the operation. The drag being com- 
pleted, the box is inverted and the block which sup- 
ported the pattern removed, leaving the latter in 
the mould. The parting having been prepared and 
the gates and risers properly arranged, the oper- 
ation of ramming up the cope is proceeded with. 
The skeleton for the cope should not only have 
lifters, but be provided with prickers or wires ex- 
tending to within a half -inch of the pattern and 
joint of the mould. The purpose of these is to 
support the sand. The cope being completed, 
the sides and end of the box are removed, the cope 
lifted off and held suspended, the pattern with- 
drawn, and the mould dressed. A bed having been 
prepared, the drag is lifted from the bottom board 
and placed on the bed and the cope placed upon it. 
One fourth of the mould is now complete, as illus- 
trated in Fig. 150. In the same way the other 
sections of the mould are prepared. When all parts 
of the mould are in place they are weighted with 
plates made for the purpose and conforming in shape 
to the sections of the mould. A curb of thin boiler- 
plate bent to a circular shape, with flanges turned 
outwardly and radially for bolting together, is 



CONSTRUCTION OF SMALL SCREIV PROPELLERS, 129 

made to encircle the mould. The space between 
the mould and the curb is rammed with sand, and 
after the pouring-gate is prepared the mould is 
ready to be poured. 

In making the core-box it is advised that it be 
made of sufficient radius to answer for the largest 
screw likely to be wanted. Screws up to four feet 
in diameter have been successfully made by this 
method. When small screws are to be duplicated 
it is best to have a metal pattern and do the mould- 
ing in a flask. The metal pattern can be advan- 
tageously made, as the foregoing explains. 

Figs. 153-156 illustrate a pattern of a globe 
valve. This is selected from correspondence be- 
cause it furnishes an excellent example of making 
what is regarded a difficult pattern. Fig. 153 
shows one half of the pattern, which serves the 
purpose of elucidation, the other half being of 
course the counterpart of that shown. The two 
pieces comprising the half-pattern are glued to- 
gether on the line MN. Both of the pieces can be 
turned in a lathe, the only hand work necessary 
being the squaring of the core-prints BB and cut- 
ting the hexagon DD. 

Fig. 154 shows one half of the main core-box ; both 
halves are counterparts and are doweled together 
with the pins EE ; the spherical part is turned out 
in a lathe. 

Fig. 155 shows a block made to fit the slot F, 
Fig. 154, and which aids to form the circular wall 
aroimd the valve-seat as well as the hole through 



l^o 



THE ART OF PATTERN-MAKING. 




Fig. 153. 













c' 


1° 







k1 










EO 




F '\ 


A' 






\ E 







I /. 


j — 


—J 






'kJ 




1 





Fig. 154. 





Fig. 155. 



Fig. 156. 



PATTERN FOR GLOBE VALVE, 131 

the seat G, The boss R is turned to the radius of 
the outside wall H, Fig. 153, while the groove / forms 
the core for the inside wall. A handle is fitted to 
the block by means of which the latter can be drawn 
out of the way before the core-box is separated. 
Two cores from this box are required for each mould. 
A straight round core made by the box Fig. 156 is 
for the stem end. The end of this core fits against 
the spherical surface of the main core at K, Fig. 153, 
To accomplish this a plug K' , with a spherical sur- 
face to match the main core, is fitted into the end 
of this box. 



XIX. 

PATTERN WORK FOR MOULDING A LARGE 
BELT-PULLEY OR FLY-WHEEL. 

A COMPLETE pattern for a large belt-pulley or fly- 
wheel is now never made to obtain a casting there- 
from, but recourse is had to expedients involving 
a comparatively small amount of pattern work. 
The pattern work to obtain such a casting consists 
of a former for the outer wall of the mould, a core- 
box for the arms, a core-box for the center core, and 
two core-boxes for covering cores. 

In beginning the mould the first pieces required 
are the former for the outside wall, shown by a 
and b, Figs. 157 and 158, respectively, and the 
center pin 0, Fig. 158. 

The former requires to be substantially made 
and consists chiefly of a base-board having a 
hole to suit the center pin, and a segment whose 
convex side is worked off to the radius of the ex- 
terior of the rim of the wheel. The segment is se- 
cured to the base-board and braced thereto in 
order to maintain a concentric position with the 
center and a right angle with the face of the board. 
o shows the center pin about which the former re- 

132 



LARGE BELT-PULLEY OR FLY-IVHEEL. 
Fig. 157. 



133 




Fig. 158. 





Fig. 159. 



134 THE ART OF PATTERN-MAKING. 

volves. In Fig. 159 / shows a plan and elevation 
of a segment of the rim, and g shows a plan and 
section of the core-box for the core which covers 
the center or hub opening of the mould. 

In Fig. 162 c shows a plan and section of a core- 
box containing a pattern of one half of an arm of the 
wheel. Two cores from this box are required for 
each arm. e shows a plan and section of the core- 
box for the cores to cover the rim opening of the 
mould. These comprise all of the pattern work neces- 
sary to enable the moulder to complete the mould. 

In beginning the mould, a level bed is first pre- 
pared and the center pin, o, Fig. 158, is located and 
fixed in place. The former is centered on the pin 
and the building of the outer wall of the mould pro- 
ceeded with by ramming green sand against the 
former and striking it off level with the upper edge 
of the segment. This completed, the former is 
moved around about two thirds of the length of 
the segment and the outer wall extended by repeat- 
ing the previous operation. The wall is continued 
in this manner until the entire circle is covered. 
The outer wall being completed, the mould is lined 
off according to the number of arms the wheel is 
to contain. The mould is then ready to receive the 
cores. It is assumed that the cores have been made 
in the mean time, while the mould was being pre- 
pared to receive them. 

The cores for the arms are the first required. 
The segment /, Fig. 159, is placed in the mould in 
the position shown by h, Fig. 160, and the bottom 



LARGE BELT-PULLEY OR FLY-IVHEEL. 
Fig. i6o. 



135 




Fig, 161. 




IS] 


p^^^^a:;- -=5 


=5=S=^ 


==^ 


1 
1 


N 




^^~P^^ 








c 




d 


— 














tJ 


y=~=5;i:~==~=:; 


==s^===:S: 


r:^=^=^ 




b4 



''^ ' L l I 



d 



1 



FiG. 162. 



136 THE ART OF PATTERN-MAKING. 

half of an arm core is set radially according to the 
line prepared for it, with its outer end against the 
segment which gauges the thickness of the rim. 
The upper half of the core is then placed upon the 
lower. This operation is repeated until all of the 
arm cores are placed, Fig. 160. The spaces between 
the cores are filled in with green sand, the segment 
being used to stop off the sand, and this completes 
the inner wall of the mould. The center core for the 
hub, which is a plain cylindrical one, is set, and the 
covering cores from box g, Fig. 159, placed. The 
covering cores from box e, Fig. 162, are next placed 
over the rim opening. 

The gates and risers having been provided for 
through the covering cores, the mould is weighted, 
and the top built up with green sand to the height 
necessary for the runners, gates, vents, etc. This 
completed, the mould is prepared to receive the 
metal. 



XX. 

PATTERN FOR AN OBLIQUE CHUTE. 

Pattern-makers occasionally meet with problems 
that are exceedingly perplexing, especially to those 
who have neglected the study of geometry ; moreover, 





Fig. 163. 

such problems are often by no means easy to solve 
even by those fairly informed in that science. Fig. 
163 shows the pattern and casting which are the sub- 

137 



13^ THE ART OF PATTERN-MAKING, 

ject of one of those problems. A cast-iron chute rect- 
angular in section is required to pass in an oblique 
direction through a brick wall 17J inches thick. It 
passes through at an angle of 35 degrees with the per- 
pendicular and 45 degrees with the face of the wall. 
As the illustration shows, the chute emerges from 
the wall with its sides parallel with the vertical 
joints of the brickwork, but its top and bottom 
are oblique to the horizontal joints of the wall. 
This obliquity results from the combination of 
angles and the rectangular section of the chute. 
There are several ways of determining the length of 
the pattern and the angle of its ends in such a case, 
and two of these ways will be described. 

In order to obtain the proper dimensions and 
angles of the pattern it is advisable to lay down full 
size the necessary views, as illustrated in Fig. 164. 
First draw the plan A, making a equal to the thick- 
ness of the wall and h equal to the base of the required 
triangle horizontally. In this case the horizontal 
angle being 45 degrees makes both sides of the tri- 
angle 17J inches. Draw the line d parallel with the 
hypotenuse c and make the perpendicular distance 
between the two lines equal to the external width 
of the chute, 14 inches, and extend d to e. Draw the 
side elevation B equal to the thickness of the wall, 
making the line / 35 degrees with the perpendicular. 
Project a line from g toward h and extend it indefi- 
nitely. Project the point i toward k and extend it 
indefinitely. Project the point / and intersect ik 
at k ; connect km : this line will give the angle of the 



PATTERN FOR AN OBLIQUE CHUTE, 



139 



chute through the wall when viewed in front elevation. 
Project the point e, and intersect the line gh at h. 
Project the point n toward and extend it indefinitely. 



~?^ 







\WM,'/MIW}}} \ y* 



1 i ! 

: SECTION i - 
OF CHUTE ^ 7 

li, 



^M/mv/mw/w/M 




-FRONT ELEVATION 



^ — -\l\i' >j 



Fig. 164. 



From the point h draw the line kp parallel with mk, 
intersecting no at o ; connect ko, and the length of the 
line so formed will equal the length of the angular 



=140 THE ART OF PATTERN-MAKING. 

side on the top and bottom of the chute at its ends. 
So far, while we have arrived at the width of the 
chute, as well as the angle of the ends on the 
top and bottom, there is no line that gives the actual 
length of the chute, because to obtain that it is 
necessary to have a view from a point perpendicular 
to the side : the side being obliquely viewed in that 
which has been drawn. The actual length of the 
chute through the wall is the diagonal line, or hy- 
potenuse of the angle whose sides are the line / 
and the line q. Draw q perpendicular to the 
end of /, making the length equal to the thick- 
ness of the wall, connect the extremities of / 
and q, and the hypotenuse r will equal the actual 
length through the wall and between the flanges 
of the chute ; this line also furnishes the basis for 
obtaining the angle of the ends of the chute on its 
sides. With the length of the line r intersect gh at 
s, and ik at /, and draw in parallel with no. Draw 
V parallel with r, making the perpendicular distance 
between the two lines equal to the external thickness 
or depth of the chute. Let v intersect tu at u; the 
length tu will then equal the depth of the end of 
the chute where it emerges from the wall, and the 
angle so formed will be the angle of the ends on. the 
side of the chute. Project and make kw equal to 
tu\ from w draw x parallel with ok, intersecting no 
at y, and the rhomboid so formed by ko and wy 
will be the figure of the end of the chute, minus the 
flange, when viewed perpendicular to the end as it 
emerges from the wall. Having determined the 



PATTERN FOR AN OBLIQUE CHUTE. 14 1 

most important part of the problem, and proper 
length and angles for the pattern, its construction 
is not difficult. The pattern complete except the 
core-box, which is a plain rectangular one, is shown 
at the left in Fig. 163. 

To begin the pattern a box or core-print whose 
cross-section equals that of the interior of the chute 
is built up of^ one-inch material; the length of the 
print iS' sufficient to allow bearings for the core 
beyond the flanks at each end. Upon the print 
the length and angles of the pattern are lined off and 
the thickness for the metal is added on in conformity 
with the lines. Where the thickness forms under- 
cuts, as at one end of the sides, the undercut pieces 
are made to be drawn separately from the body of 
the pattern ; they are secured in place by draw-pins. 
After the thickness is completed the flanges at the 
end are fitted to the pattern and secured by draw- 
pins ; they remain in the sand and are drawn out after 
the body of the pattern has been lifted from the sand. 

Another way which the writer has often used with 
great advantage and unvarying success in working 
out difficult problems of this character is to make a 
wood model to a convenient scale and develop the 
object from it. He would especially recommend 
this method where a number of different angles 
are involved, because it enables one to comprehend 
the problem more readily by having the chief fea- 
tures of the object under view, thereby impressing 
them more deeply on the mind and making mis- 
takes less liable. 



142 



THE ART OF PATTERN-MAKING. 



Fig. 165 shows a model of all that is necessary 
to solve the present problem, and in making the 
pattern it would save tenfold time spent in making 
the model. It is not necessary that such models 
should be very elaborate, but accuracy is abso- 





FiG. 165. 

lutely essential. It so happens in this case that 
the angles of the ends of the chute agree with those 
with which it passes through the wall, 3 5 degrees and 
45 degrees, or so near to them that they answer 
practical purposes; but this result does not follow 
as a rule for any combination of angles. 

A problem of the foregoing character was once 
submitted to the author after its solution had baffled 
the efforts of several excellent draughtsmen for a 
number of days, and he solved it with the aid of a 
model which required less than two hours to make. 



XXL 
PATTERNS WITH BRANCHES. 

Fitting branches to patterns, such as pipes and 
valves, by the usual cut-and-try method is tedious 
and consumes unnecessary time, especially when the 
body to which the branch is to be fitted is of some 
peculiar form. By preparing paper patterns of 
the line of juncture of the two parts, and marking 
this line off on the branch, the work is more skil- 
fully performed and the job expedited. Several 
different forms of preparing these patterns are here 
elucidated. When the principles involved in these 
problems are mastered, they can be applied to a wide 
range of work. 

When the body and branch are of equal and uni- 
form diameter, it is simply necessary to first cut the 
end of the branch on either side at 45 degrees with 
the center line, as at A in Fig. 166. The line so 
produced on the circumference of this branch will 
be that of its juncture with the body, and when the 
branch is cut across to this line it will fit the body 
if the work is accurately performed. 

B presents a problem not so simple as the pre- 
vious one. Here the branch is smaller in diameter 

143 



144 



THE ART OF PATTERN-MAKING. 




Fig. 1 66. 



PATTERNS IVITH BRANCHES, 145 

than the body to which it is to be fitted, and a paper 
pattern is to be made to mark off the Hne of juncture. 
Lay down a plan and a* section of one half of the 
body and branch, as a and h\ divide the semicir- 
cumference of the branch a into any number of 
equal parts, so as to have a line in the center, and 
number the intersections. From these intersections 
project lines intersecting the curve of the body h. 
Now tack down a piece of suitable paper, c, in the 
position shown, and on it draw two parallel lines, as 
o and 6, whose distance apart is equal to the circum- 
ference of half the branch a. Divide this distance 
into the same number of parts as that of a, and draw 
lines parallel with the outside lines. From the 
intersections of the lines from branch a with the 
body project lines intersecting the lines on the 
paper c with corresponding numbers. A curve 
drawn through these intersections will give the 
developed curve of juncture of the branch with the 
body, and as in this case both halves of branch are 
alike, the pattern will answer for both. To arrive 
at this developed curve it is not absolutely necessary 
to lay down the plan view when both the branch and 
body are cylindrical and are at right angles; but 
when it is desired to show the projected curve of 
the juncture, the plan view is necessary, and the 
intersections for it are obtained by projecting from 
the sectional views, a and h, to ordinates with corre- 
sponding numbers on the plan. 

Fig. 167 shows a branch fitted diagonally to the 
body of the pattern. To obtain the developed 



146 



THE ART OF PATTERN-MAKING. 



curve in this case the method to be pursued is similar 
to that in the previous problem. The plan and sec- 
tional views are to be made and divided as previously 




Fig. 167 

explained, and the projected curve of the juncture 
of the body and branch obtained by projecting 
from the intersections on the section h of the body 



PATTERNS IVITH BRANCHES, I47 

to ordinates correspondingly numbered on the plan 
view of the branch. The developed curve of the 
juncture is then obtained by placing the paper along- 
side of the branch and projecting from the latter. 
Lay off on the paper two lines parallel with each 
other, and with the axis of the branch make the dis- 
tance apart of the lines equal to the circumference 
of one half of the branch, and divide this distance 
into the same number of equal parts as that of the 
branch. From the intersections which produced 
the projected curve of juncture of the branch with 
the body on the plan, project lines at right angles 
to the axis of the branch to the ordinates on the 
paper, intersecting those correspondingly numbered. 
A curve drawn through these last intersections will 
give the developed curve of juncture. 

Fig. 1 68 illustrates the body of a pattern which 
is not cylindrical, but which has a cylindrical branch 
fitted to it. With many workmen, at first sight, 
it would seem a very difficult problem to work out 
the developed curve of juncture of branch with 
body in this case, but if the previous examples 
have been studied and mastered, it will be found 
quite an easy matter to do so. 

The plan view is to be first laid down, or so much 
of it as is covered by the branch. Draw a section 
of one half of the branch in the position shown by a, 
and divide its circumference as in previous examples. 
Through these intersections draw lines parallel with 
the axis of the branch, extending across the body, 
thus cutting the body into as many sections as lines. 



148 



THE y4RT OF PATTERN-MAKING. 




6^5 4 a 



Fig. 168. 



PATTERNS IVITH BRANCHES. 149 

These sectiorxS of half the body are to be drawn 
below the body in the position shown by 6, and 
numbered correspondingly to those on the body. 
A section of the branch is drawn in the position 
shown by c, and the half -circumference divided the 
same as that for the plan view. From these inter- 
sections lines are drawn intersecting the sections of 
the body correspondingly numbered. From these 
last intersections both the developed and the pro- 
jected curve of juncture are obtained by following 
the method of doing so explained in the previous 
examples. 

It is sometimes required to fit a branch or boss 
on a body away from the center line of the latter. 
Fig. 169 shows two such cases. In the upper view, A , 
the branch is at right angles to the body and to one 
side of its center. To obtain the developed curve 
of the juncture of the branch with the body in this 
case lay down the branch and so much of the 
body as necessary in both end and side views. 
Draw end views of the branch and divide them into 
equal parts; from these intersections project lines 
parallel with the axis of the branch and intersecting 
the body. Number these ordinates correspondingly. 
Tack down the paper in the position shown and draw 
two lines parallel with each other and with the axis 
of the branch ; make the distance apart cf the two 
lines equal to the circumference of the branch. 
Divide this distance into the same number of equal 
parts as the end view of the^branch, and draw ordi- 
nates parallel with the outside lines. Number the 



15© 



THE ART OF PATTERN-MAKING. 





Fig. 169. 



PATTERNS fVITH BRANCHES. 151 

ordinates to correspond with those projected from 
the end view of the branch. From the intersection 
of the ordinates on the branch with the body project 
lines intersecting the ordinates correspondingly num- 
bered on the side view and on the paper ; a curve drawn 
through these intersections on the side view will give 
the projected curve, and a curve drawn through 
the intersections on the paper will give the developed 
curve, of the jimcture of the branch with the body. 

The lower view, B, shows the branch located to 
one side of the center of the body as in the previous 
case, viewing the body on the end ; but viewing the 
body on the side, the axis of the branch is inclined 
to that of the body. 

To obtain the projected curves of juncture in this 
case draw the two views as before and draw ordinates 
on the branch projected from intersections on its 
end view. From the intersections of these ordinates 
with the body on the latter' s end view project lines 
intersecting the ordinates correspondingly num- 
bered on the side view. A curve drawn through 
these latter intersections will give the projected 
curve of juncture of branch with body. To obtain 
the developed curve tack down the paper in the 
position shown, and upon it draw two lines parallel 
with each other and with the axis of the branch on 
the side view, making the distance between the lines 
equal to the circumference of the branch. Divide 
this distance into the same number of equal parts as 
the branch, and draw ordinates parallel with the two 
end lines. Number the ordinates to correspond 



152 THE ART OF PATTERN-MAKING. 

with those on the branch. From the intersections 
of the ordinates on the branch with the body, as 
shown in the side view, project lines at right angles 
with the axis of the branch intersecting ordinates 
correspondingly numbered on the paper. A curve 
drawn through these last intersections will give 
the developed curve of the juncture of the branch 
with the body. 

Where there is frequent occasion for fitting 
branches when making plain patterns, such as 
pipes, etc., a device like that shown in Fig. 170 will 
be found a great advantage. It consists chiefly 
of a base-plate having a true surface, with a spindle 
fixed near one end and perpendicular to the true 
surface of the plate ; also a head which has both a 
sliding and a revolving motion on the spindle. The 
sliding head carries a radius-bar set at right angles 
to the axis of the spindle. The radius-bar is ad- 
justable to suit different radii, and one end is pro- 
vided with a scriber held in a clamp bearing so that 
it can be adjusted to suit different diameters of 
branches. 

A and B are cradles to which the work is secured 
by w^ood-screws while being operated upon. The 
cradles can be made of wood, but are much better 
when made of metal and finished accurately. There 
should be a center line scribed on the surface of the 
base-plate parallel with its sides and intersecting 
the axis of the spindle to serve as a datum line for 
setting the cradles when the work is to be marked. 



PATTERNS tVITH BRANCHES. 



153 




154 THE ART OF PATTERN-MAKING. 

The cradle A is intended for parted work, and B for 
work not parted. 

The device is equally handy whether the boss or 
branch is set at right angles to the body of the pat- 
tern or at any other angle, or whether it is to set away 
from the center line of the body. In the former 
case it is only necessary to secure the work at the 
desired angle in the cradle, or, where it is set to 
one side of the center line of the body of the pattern, 
to set the cradle accordingly on the base-plate 
while the curve is being scribed on the work. 

After the work is scribed, which will be on the 
upper side as it sets in the cradle, the latter can be 
taken to the band-saw and the work cut to the line. 
If the entire operation has been carefully and accu- 
rately done, the branch will need very little further 
fitting to allow it to be secured in the place intended 
for it. 



XXII. 

TEETH OF GEAR-WHEEL PATTERNS. 

The increasing use in machine construction of 
cut gear and also of machine-moulded gear has 
somewhat lessened the extent that gear-wheel work 
formerly held in the trade of pattern-making. But 
notwithstanding this tendency gear-wheel work is 
still a very important factor in the trade of pattern- 
making because of the skill and expertness required 
in its performance. There are few patterns of the 
class that are regularly made for machine castings 
that require greater skill and expertness to com- 
plete than a bevel- wheel pattern. 

As to the best method of working the teeth and 
attaching them to the rim of a gear-wheel pattern 
there has been much discussion amongst pattern- 
makers. Fig. 171 shows five methods of secur- 
ing the teeth to the rim; each of these has its 
advocates. A gear-wheel pattern to be made prop- 
erly should be made accurately; it matters not how 
well made otherwise, if not accurate it is not suited 
for the purpose for which gear-wheels are intended. 
Of the different methods shown here the author is 
decidedly in favor of securing the teeth as shown 
by No. 5. This method of securing the teeth to 

155 



156 



THE ^RT OF PATTERN-MAKING 





Fig. 171. 



TEETH OF GEAR-JVHEEL PATTERNS. 157 

the rim is amongst the eadiest practiced, and for 
accuracy and durabih'ty has no superior. The 
objection urged against this method that it is 
difficult to form suitable fillets at the roots of the 
teeth, owing to the delicacy of the edges there, is of 
small moment, because with care and the aid of 
sandpaper and shellac satisfactory fillets can be se- 
cured. The devices shown in connection with the 
teeth and rim of the wheel are intended to facilitate 
the working and attaching the teeth to the rim 
when method No. 5 is adopted. A, B, C, are respec- 
tively a plan, an end, and a side view of a com- 
bined box clamp and gauge by means of which the 
size and shape of the dovetail tenons on the tooth- 
blccks are worked. The gauge, a, is intended for 
use when cutting the dovetail slots in the rim ; it is 
made of hard wood and equal in length to the face 
of the rim, and has a center line scribed through its 
length and on the ends. The angle of the sides 
should be about 22° 30' with the center line, and 
the taper in length f inch per foot. The gauge in 
use is secured to the rim by two sharp-pointed wire 
brads, which are allowed to project to enable them 
to be readily withdrawn to change the position of 
the gauge. After the rim has been stepped off and 
lined, the gauge is secured to the rim by the pointed 
bi;ads to coincide with a center line for a tooth. 
The saw, 6, is applied and kept close to the side of 
the gauge while sawing the rim to the line scribed 
on the rim for the depth of the slot. After the 
sides of the slot have been sawed and the gauge 



158 THE ART OF PATTERN-MAKING. 

removed, it is advisable to saw one or two kerfs 
between those outside. These will facilitate the 
removal of the material in working out the slot. 
The box, ABC, should be made substantial and of 
a size to allow its use for different sizes of teeth. 
The small sizes of teeth can be worked in the box by 
fitting a liner under the block and making a wedge, 
d, to suit the space between the block and the side 
of the box. The bottom of the box should be of 
sufficient thickness to allow the box to be held in 
the bench-vise while the dovetails on the blocks are 
being worked. The top of the box, c, which is the 
gauge for the taper and bevel for the dovetail 
tenon, is adjustable. The plane, e, is a rabbet 
beveled on the face to suit that of the gauge, a. A 
strip is secured to the side of the plane which, by 
bearing on the top of the box, c, gauges the depth 
of the dovetail. After one side of the dovetail 
tenons have been worked on the blocks the top, c, is 
reversed in angle and the remaining sides worked. 
The dovetail tenons should be made a trifle full for 
the slots, as a little fitting will be found necessary 
even when pains have been taken to insure accuracy, 
and for this reason, also, they should be somewhat 
longer than the width of the rim; they can be cut 
to the required length after being fitted into the 
rim. 

If the teeth are to be cut by machinery, the blocks 
are secured to the rim by applying glue to about 
one-half inch at the large end of the dovetail. 
Gluing at one end only is to allow for any possible 



TEETH OF GEAR-IVHEEL PATTERNS. 159 

shrinkage of the rim. If the teeth are to be worked 
out by hand, the blocks, after the shape of the teeth 
have been laid off, are backed out, each being 
marked as it is removed from the rim ; they are then 
worked in the usual way by being held by a hand- 
screw in the bench-vise while being shaped. In 
finally replacing the teeth in the rim three or four 
should not be glued ; these should be properly 
marked: they are for the purpose of allowing the 
moulder to back them out to mend the mould 
should that become necessary. 

As to the best material for making gear-wheel 
patterns there is nothing better than clear, soft, 
white pine for the body of the wheel and straight- 
grained cherry for the teeth. All of the material 
of course should be thoroughly seasoned and dry 
when used. 



XXIII. 

BELT-PULLEYS AND FLY-WHEELS. 

In Fig. 172, I represents a fly-wheel; 2, a belt- 
pulley; and 3, a gear-wheel design. Pattern- 
makers are frequently required to make patterns 
of wheels and pulleys without the aid of a prepared 
drawing. In such cases they will necessarily do their 
own designing and determine the proportion of 
the several parts. The following rules and formulae 
will enable those unaccustomed to such matters 
to determine the various dimensions for wheels and 
pulleys within eight feet diameter; 

a = width of face ; 

h = thickness of rim ; 

J = diameter of wheel or pulley; 
e= " " shaft 

/ = *' ** hub = i".8 X^, for single pulley and 
eXi^.g for double belt-pulley; 
g:= length of hub; 
h = .o^Xk-\-x = width of arm at hub ; 

f=- = thickness of arm at hub; 
2 

^= length of arm; 

160 



BELT-PULLEYS AND FLY-IVHEELS. 



i6i 




Fig. 172. 



1 62 THE ART OF PATTERN-MAKING. 

:x: = width of arm at rim; 

y=-= thickness of arm at rim. 

The thickness of the edge of rims should be ".25 
for double- and ".2 for single-belt pulleys, the thick- 
ness to increase ''.125 per foot to center of rim. 
The arms should be oval in section, the radius of the 
edges made about one eighth of the width of the 
arm. The application of formulas is apt to cause 
timidity in some mechanics when solving problems, 
but by following the examples worked out the 
dimensions of the details for any other diameter 
than that given may be easily arrived at by substi- 
tuting the given diameter. 

Example. 

It is required to find the size of arms and hub for 

a single belt-pulley 48'' diameter for 3'' shaft. 

Formula: x = " .^^j^-^ .o^d. 

^ = "•375 + 1-92 =2^.3 = width of arm at rim; 

oc 2 "? 
-1; = - = -^ i.ir =thickness of arm at rim ; 

^ = 24 — 3=21 =length of arm. 

/i = 2iX.o5 + 2.3= width of arm at hub ; 

2 "^ 
i = ■— ^ = 1.1';= thickness of arm at hub ; 
2 ^ 

/ = 3 X 1.8 = 5.4 =diameter of hub. 

A close approximation of the length of arm for 

pulleys can be obtained by subtracting the diameter 

of shaft from the radius of the pulley, as done in the 

above example. 



BELT-PULLEYS AND FLY- IVH EELS, 163 

Required the size of arms and hub for double-belt 
pulley 48 inches in diameter for 3-inch shaft. 
Formula: x-=".%^-\- .o/^d. 

Example. 

.04^ = 1.92; 

:t = .85 + 1.92 =2". 8 = width of arm at rim; 

^ 2.8 ,, . . . 

y = -^ — = I ''.4 = thickness of arm at rim; 
-^ 2 2 

^ = 24 — 3 =21" = length of arm; 

h = 2i X.o5 + 2''.8 = 3".85 = width of arm at hub; 

/ = 3 X1.9 = 5". 7 = diameter of hub. 

i = — — = 1.0= thickness of arm at hub ; 
2 ^ 

g = length of hub, and will vary, according to diam- 
eter of pulley and width of face, from one 
and a half to three times the diameter of shaft. 
For heavy rim wheels, such as fly-wheels, c, repre- 
senting the volume of the rim, becomes a factor and 
rr-.85^|-.04J + .i53C. 

Required the size of arms and hub for fly-wheel 
60 inches in diameter with a rim section (ab) of 
4X6 inches, shaft 3.5 inches diameter. 

Example. 

i\; = .85 + 2.44-.75 = 4 inches = width of arm at rim; 

X 4 
a; = — = - = 2 inches = thickness of arm at rim ; 

''22 

^ = 30— (3.5 + 6) =20.5 in. =length of arm; 

/z = 20. 5 X .05 + 4 = 5 in. = width of arm at hub ; 



1 64 THE ART OF PATTERN-MAKING. 

^=- = 2.s in.= thickness of arm at hub ; 

2 

/ = 3. 5X2=7 inches = diameter of hub. 

For fly-wheels, also for pulleys when the pattern 
is likely to be used for other purposes than that for 
which it was specially designed, it is advisable to 
make the diameter of hub double that of the shaft. 
In so doing it adds but a small amount to the weight 
of the pulley, but it has the advantage of making 
the pattern available for a somjewhat larger shaft, 
without alteration, if wanted for such. 

In the case of fly-wheels like the foregoing exam- 
ple it will be found that the aggregate widths of the 
arms exceed the circumference of the hub, and when 
the arms are joined by a curve, a web will be formed 
around the exterior of the hub which greatly strength- 
ens the latter. The proportions of fly-wheel rims 
will vary according to the fancy of designers, except 
in cases where a belt is to be used on the rim. 
Some will prefer to make the face the larger dimen- 
sion, while others will make the side of the rim the 
larger dimension. In either case good proportions 
for rims are as 2 and 3. 

When designing arms, etc., for gear-wheels the 
formula for double-belt pulleys can be used, with 
the addition of a web on the interior of the rim 
joining the arms at that part. The thickness of 
rim of a gear-wheel is usually made equal to that of 
the root of the tooth. 

The number of arms a pulley should have will 
va.ry according to the diameter. Up to 10 inches, ■ 



BELT-PULLEYS AND FLY-IVHEELS, 165 

a solid web, or 4 arms ; from 10 to 18 inches diameter, 
5 arms; from 18 to 42 inches, 6 arms; and from 42 
to 72 inches, 8 arms. 

While it is advisable to abolish all sharp corners 
in castings, great care is necessary in applying 
fillets, as very large fillets, under some conditions, 
may become a source of weakness to a casting 
instead of adding strength. A casting is strongest 
when the metal is most imiformly distributed. 



XXIV. 

STANDARD PATTERNS. 

Standard patterns when made of wood and 
which are often used should be made very durable. 
They should be made wholly or in part of hard 
wood, such as mahogany or cherry. Where dowel- 
pins are necessary they should be of metal. The 
metal dowel-pin should be about ij" long and 
cylindrical for about ^'^ from the plate, then taper 
yV' to the point, which should be rounded. Made 
thus the plate can be set a little below the joint of 
the pattern and not interfere with the parts joining 
together properly. Wood dowel-pins answer their 
purpose very well for ordinary patterns and are 
cheaper than metal, but when a pattern with wood 
pins is often used the pins are liable to stick by 
becoming damp and swelling. When this occurs, 
very likely the moulder will enlarge the holes to 
such an extent that the doweled parts will not retain 
their proper position while being rammed up in the 
mould, and the result is a distorted casting. Rap- 
ping- and draw-plates are great pattern-savers and 
will well repay their cost when fitted to patterns 

I66 



STANDARD PATTERNS, 167 

that are used for many castings. There are several 
kinds of rapping- and draw-plates on the market 
very reasonable in price. Unless for a very large 
pattern, plates combining both rapping and draw 
features are the most convenient. 



XXV. 

GLUE AND ITS USE. 

Glue is indispensable in pattern work, but it is 
not every pattern-maker that can do a first-class 
job of gluing. The first essential for a good job of 
gluing is good glue. The author has always found 
the best Irish glue thoroughly reliable. With this 
glue in the hands of a competent workman who 
understands its use, there is no excuse for a bad 
gluing job. The glue should always be applied 
hot. Prepared liquid glues that can be applied 
without heating them are very convenient and will 
hold well for a while, but their adhesiveness seems 
to deteriorate with age and they are not so durable 
as glue applied hot. When large surfaces are to 
be glued the work should be warmed where possi- 
ble. Pattern-shops are not usually provided with 
a special room that can be heated for gluing work. 
Where there is no special room for gluing up work 
it is advisable to heat the work previous to applying 
the glue. A good substitute is a steam-box. Such a 
box can be made of tongue-and-groove partition- 
stuff and need not be very expensive. A conve- 

i68 



GLUE AND ITS USE. 169 

nient size inside is about 16 ft. 6 in. long, 24 in. wide, 
and 24 in. deep. The cover should be hinged and 
in two parts as to length. A coil of i-in. steam- 
pipe running along the bottom of this box should 
supply the heat. The box should be located con- 
venient to the glue-heater. 



XXVI. 

LOOSE PIECES. 

Loose pieces on patterns, although objectionable, 

cannot in many cases be avoided. They are often 

less objectionable than cores. When it becomes 

necessary to choose between a core and a loose 

piece the latter will generally prove the better 

because it will insure a truer casting. A core is 

especially liable to become misshapen by dressing 

and handling. Loose pieces are usually attached to 

patterns with draw-pins. Common brads with the 

end bent near the head make excellent dr?„w-pins. 

In some cases it is advisable to fit loose pieces with 

dovetail tenons because when so fitted they are 

less liable to be misplaced while ramming up the 

mould. In fitting loose pieces with dovetails it is 

the practice with many pattern-makers to make the 

tenons parallel in thickness and have the taper on 

the two bevel edges only. This is objectionable, as 

they are liable to stick when so made. To insure 

the pattern being drawn easily and leaving the 

loose piece in the mould without distorting it, the 

dovetail tenons should be tapered both in width 

and thickness. 

170 



XXVII. 
WOOD LAGGING FOR AN ELBOW. 

In covering steam-pipes with materials of low heat- 
conducting properties for the purpose of retaining 
heat that would otherwise be dissipated, it is neces- 
sary, especially on vessels, to cover the non-con- 
ducting material itself, and thus increase its dura- 
bility while giving it an appropriate finish. For this 
outside covering black-walnut lagging is largely 
employed. This work is usually done by pattern- 
makers. 

In work of this kind peculiar shapes are frequently 
encoimtered which tax the skill and ingenuity of 
the workman in his effort to satisfactorily cover 
them. The most common are bends of pipes. 

Figs. 173 and 174 show the different stages in 
constructing a right-angle bend for a pipe of wood 
lagging. On a suitable board, circles of the exterior 
and interior diameters of the bend are described, 
and from these the number of pieces or segments 
to compose the bend is determined. The cuts 
show a bend composed of twelve pieces, six in each 
half. 

171 



172 THE ART OF PATTERN-MAKING, 

The material is first brought to the required 
thickness, according to the location of the several 
segments in the bend, as shown by i, 2, 3, 4, 5, and 
6, Fig. 173. These are all the pieces which compose 
one half the bend, 6 joining next to i, 5 next to 2, 
and 4 next to 3. The different segments can be laid 
off directly on the material, but by the use of pre- 
pared templets the material can often be worked 
to better advantage. 

The figures show a plan and section of the 
different pieces and clearly illustrate the method of 
laying them off. 

After the curvature of the pieces has been worked 
out, the next thing in order is to bevel the edges 
that the pieces may closely join when assembled. 
This bevel is required to be a radial line of the cir- 
cles. Fig. 174. The thicker or outside segments are 
most conveniently beveled from the sides which are 
to be curved, and the thinner or inside pieces from 
the top or flat side. 

The required thickness of the segments being 
gauged after beveling, they are worked to the ex- 
terior circle by templet. The insides are next worked 
out, which may be done roughly, as with these parts 
it is only necessary to approximate the circle. 

When preparing to assemble the segments an 
outline of the bend is laid off on the board, and to 
this are secured semicircular blocks of the inside 
diameter at each end of the bend. As the segments 
are assembled, they are made to fit these blocks, 
which serve at once as guides and supports. Pieces 



IVOOD LAGGING FOR AN ELBOIV. 
Fig. 173. 



173 




Fig. 174. 



174 THE ART OF PATTERN-MAKING. 

of pine block glued to the segments will be found 
convenient for securing them to the board upon 
which they rest. These blocks are easily removed 
when the bend is to be finished. 

If the segments have been accurately worked 
and have not warped, little fitting will be necessary 
when assembling them. After a segment has been 
fitted and is ready to be doweled to its neighbor, a 
bead is worked on one edge. For this purpose a 
piece of saw-blade or other thin steel filed to form a 
bead and fixed to a gauge made for the purpose is 
convenient, the bead being formed rather by scrap- 
ing than by shaving. 

When one half the bend has been completed, 
except to finishing, it is to be inverted, and the other 
half assembled upon it, this last being performed 
in a manner similar to that of the previous half. 

If preferred, both halves may be assembled on the 
board, right and left, and if due care be exercised 
they will match properly. 



XXVIII. 
THE LATHE AND LATHE-WORK. 

The first essential for doing good lathe-work is a 
good pattern-maker's lathe, which should be per- 
fectly balanced and run steadily. When not spe- 
cially designed for very small work it should be 
provided with a traveling carriage and slide-rest, 
also with outside or overhanging face-plate and 
floor-stand. The various appurtenances, such as 
chucks, face-plates, drivers, centers, etc., have much 
to do with a lathe's usefulness. 

Some ingenious and handy fixtures for the 
lathe have been described. They are here repro- 
duced, with some modifications and additions, in 
Figs. 175 and 176. 

Referring to Fig. 175, a represents a driver which 
possesses some points of merit for large work. 

With the ordinary spur driver with the spurs 
fixed and projecting nearly to the point of the 
center it is often difficult to readily swing the work 
between the centers. With this driver the chisel- 
points which do the driving are made adjustable by 
means of a collar with a screw-thread on its inner 
circumference. The driving points move in grooves 

175 



176 



THE ART OF PATTERN-MAKING. 




C 



d 





-^rJi'T 



9 



•cr'T^' 



uz 



7 



^ 





c 



/ 



Fig. 175. 



THE LATHE AND LATHE-IVORK. 



177 




J 



h 




Fig. 176. 



178 THE ART OF PATTERN-MAKING, 

cut into the projecting end of the driver. These 
are threaded on their outer surface to match the 
collar. By this arrangement the driving points 
can be kept well out of the way until the work is 
swung between the centers. After the work has 
been swimg the driving points can be moved out 
and forced into the work by revolving the collar 
and allowing it to bear against the end of the body 
of the screw-box. When the driving points are to 
be released the collar is revolved in the opposite 
direction. The points can then be withdrawn. 

h shows another kind of driver, convenient 
where it becomes necessary to remove and again 
replace the work in the lathe. In such cases 
it insures the work being centered in the second 
instance exactly as it was in the first. The con- 
centric rings on the driver should have the taper 
on their inner circumference and have their periph- 
ery parallel with the axis of the lathe. This will 
prevent any tendency, especially with parted work, 
to move outward. 

c shows the ordinary socket-chuck to screw on 
the spindle. In some cases the hole for holding the 
work is wrongly made square. It should always 
be made circular and have a taper in the proportion 
of one inch per foot. 

d shows a driver similar to h intended for smaller 
work and to fit the socket in the lathe-spindle. 

e shows a good form of driver. It is made cylin- 
drical and then milled away at the end so as to leave 
a central spur and four chisel-points for driving. 



THE LATHE AND LATHE-IVORK. 179 

/ shows a tail-stock center with a central spur 
and a concentric ring. In using this center it is 
good practice to fill this cavity with tallow or Albany 
grease before inserting it into the work, as it is diffi- 
cult to oil when in the work. Every pattern-maker 
knows the difficulty even when the work has been 
centered in the first instance, of keeping it so in the 
lathe when using the ordinary single-spur centers. 
With the concentric-ring centers and drivers there 
is little liability of the work shifting after once 
being secured in the lathe, and should the work 
require removal from the lathe, it can be replaced 
exactly as it was before removal. 

g shows a handy chuck where it is important to 
have the work accurately parted in the center. One 
side of the work is made longer than the other, and 
this long side is secured to the chuck by screws. 
The chuck's construction and application are so 
plainly shown as to make further explanation 
unnecessary. 

In preparing jointed work for the lathe, espe- 
cially that which is to swing between centers, and 
when sufficient time will permit, have the pieces of 
ample length and glue them together outside of 
the finished length. The glued part can be cut off 
after the work is removed from the lathe. 

In Fig. 176, h shows a face-plate with a central 
boss finished to size and trued on the spindle of the 
lathe. The boss is to fit a hole bored into the work 
to be operated upon. A convenient size for the 
boss is one inch diameter and one-quarter inch 



l8o THE ART OF PATTERN-MAKING. 

long. The dotted lines serve to illustrate one of 
the most satisfactory operations of this simple fix- 
ture. The blank shown is finished on both sides. 
In operating on the first side a recess is turned in 
the center of the exact size to fit the boss on the 
face-plate. This insures the work being reversed and 
rechucked with accuracy. The recesses are also 
convenient for locating core-prints which are to be 
turned with a pin to fit the recess. 

i shows a similar face-plate of smaller dimen- 
sions. The wood-screw shown in the center of 
the face-plate is preferable to the usual taper 
screw, because it is not so liable to split the work. 
The screw should fit the hole in the plate tight, but 
not so much so as to prevent its being backed out 
in case it is desired to use screws of different lengths. 

For boring the recess to fit the center boss on the 
face-plate, a bit, m, should be prepared — a Forstner 
bit preferred. The bit should be kept handy to 
the lathe and not allowed to be used for any other 
purpose than that for which it is intended. 

A great advantage will result from the adoption 
of a system for core-prints and have all core-prints 
conform to it. All core-prints for both drag and 
cope should be made tapered and core-boxes made 
so that the cores will fit the impressions made by 
the prints and not have cores larger than the prints, 
as is too often the case. In making core-boxes for 
cores which set vertically in the mould, it is the com- 
mon practice to make the lower or drag print slightly 
tapered and the end of the core-box straight or cylin- 



THE LATHE AND LATHE-IVORK. i8l 

drical. Thus made there is always a liabiHty of the 
core inchning, for the reason that the core when being 
set is apt to cut into one side of its seat as shown 
at I. When the print is given sufficient taper and the 
core-box made to suit it, there is less liability of the 
core not being properly set as shown at n. The pin 
on core-prints will be found advantageous when at 
any time it is desired to change the size of the core. 
A good standard for the taper of drag-prints is one- 
eighth inch in diameter for one inch in length ; and 
for cope core-prints, one-quarter inch in diameter 
for one inch in length. 

To facilitate the practice of this system of core- 
prints it is necessary to provide gauges similar to 
those shown at k for the drag, and at / for the cope 
core-prints. By means of these gauges the pins 
on the core-prints and the recesses for them in the 
pattern can be sized. Also the size and length of 
the prints gauged. A convenient place near the 
lathe should be provided for the gauges and bit, and 
care taken that they are always in their place when 
wanted for use. 



XXIX. 

HOW TO MAKE A WOODEN FACE-PLATE. 

A COMMON way of making wooden face-plates for 
the lathe is to secure a plain wood plate to a cross. 
When using hand- screws with a plate made thus 
some of the screws are required to be set open to suit 
the thickness of the work and plate, and others to 




Fig. 177. 

suit the thickness of the cross in addition. This 
condition often causes vexation by picking up the 



182 



HO^V TO MAKE A WOODEN FACE-PLATE. 183 

wrong screw in the hurry necessary when gluing 
up work. The annoyance thus occasioned may be 
avoided by securing segments of the thickness of 
the cross around the edge of the plate between the 
cross (see Fig. 177), then all hand-screws are required 
to be opened alike. 



XXX. 

MARKING, RECORDING, AND STORING 
PATTERNS. 

It is now being recognized that patterns repre- 
sent a large amount of money with some establish- 
ments, and economy requires that they should be 
properly cared for. Every concern using patterns 
to any extent should have a system of marking, 
recording, and storing them, and should not depend 
on the memory of persons for their identity and 
location. With a proper system any person of 
ordinary intelligence can be placed in charge of the 
pattern storage in case of the absence of the regular 
man whose business it is to take care of the patterns 
when the foundry has finished with them. 

The nomenclature of machines and their various 
parts should originate and be decided upon in the 
draughtsmen's department, and this information 
should always be noted on the drawing. It is too 
often the case that the name of the machine or its 
parts is left to be decided upon in the pattern de- 
partment. By the name, etc., being noted on the 
drawing there would in many cases be less difficulty 

in identifying a pattern. 

184 



MARKING, RECORDING, AND STORING PATTERNS. 185 

Several systems are in use for marking and record- 
ing patterns, each having its merits and demerits- 
Some simply stencil or paint a number on the pattern 
and have a pattern accession-book in which the 
patterns are recorded. This system to be efficient 
needs to be combined with their proper care and 
storage, a feature too often neglected. This system 
has the disadvantage of the number, etc., becoming 
obliterated by continued use and neglect; but this 
objection can be overcome by renewing the stenciling 
when obscurity by wear becomes liable. With 
proper care stenciling will prove more durable than 
one would suppose who has had no experience with it. 

Another method of marking is to stamp the 
number and name on the patterns with stencil-cutters. 
This indelibly marks it. The nuraber of the pat- 
tern with whatever other necessary information in 
connection with it is recorded in a pattern-book. 

It is desirable, especially when standard or particu- 
lar lines of machines are manufactured, to have some 
mark to appear on the machine or its parts to enable 
them to be readily identified and to facilitate filling 
orders for such machines or their parts. 

The system I would recommend, especially for 
establishments using a large quantity or a great 
variety of patterns, is: 

I. Classify the patterns by placing in a class all 
similar machines. Where a machine is extensive 
and consists of many parts it may be given a class 
mark of its own. The different classes to be in- 
dicated by a letter or combination of letters. 



i86 



THE ART OF PATTERN-MAKING. 



2. Give each pattern a number. Where a pat- 
tern consists of a number of pieces, give each piece 
the same number as the main part of the pattern. 
Mark all core-boxes to correspond with class and 
number of their respective patterns. 

3. Mark the pattern, its loose pieces, and core- 
boxes by stamping with stencil-cutters, and in 
addition secure raised letters and figures, for class 
and numbers, to the pattern so that they will appear 
on the casting. The advantage of stamping be- 
sides the lead figures, etc., is that if a figure becomes 



3Iachine 


Chamber for 
12 Stop Valve, 


Parts 


3 Pieces 
4 C. Boxes, 


Castings 


1 right, lleft. 
Cast Iron, 


Hemarks, 

Made to cJiange to 

right and left* 



Fig. 178. 



lost from the pattern, the correct number will re- 
main in the stamp and the loss will thereby be 
more readily discovered. In affixing the lead letters 
and figures to the pattern it is advisable to nail 
them and not depend on shellac alone to hold them. 
4. Provide small printed forms, similar to the 



MARKING, RECORDING, AND STORING PATTERNS. 187 

sample shown in Fig. 178, to be filled in with pen 
and ink. The information on these forms, which 
can be about 2" X 2", should give the name and 
part of the machine the pattern is intended for, the 
number of pieces composing it, also the number 
of core-boxes belonging to the pattern, the number 
and kind of castings, and any other information 
deemed essential. These forms are to be fastened 
with shellac to a part of the pattern subject to the 
least wear, and when fixed are to be given two coats 
of shellac. Thus treated they will prove quite dur- 
able. The miscellaneous is likely to be the largest 
class of patterns. There are, however, many pat- 
terns of this class carried from year to year and 
never used that should be destroyed after being 
employed for the purpose for which they were made. 
The pattern storeroom should not be encumbered 
with a lot of patterns not likely to be used again for 
the purpose for which they were made. 

For recording the patterns the card system pos- 
sesses many advantages over recording in a book. 
The cards can be in duplicate or triplicate as deemed 
desirable for use in the drawing-room, pattern-shop, 
and pattern storeroom. All information about the 
pattern likely to be needed can be recorded on the 
card. Moreover, any change that becomes neces- 
sary can be readily noted on the card or a new 
card substituted. A desirable size for the record- 
ing cards is 3 J" X 5^". A sample card is here shown 
(Fig. 179). 

The pattern storeroom should be divided into sec- 



i88 



THE ART OF PATTERN-MAKING. 



Class 


A 


dumber 


1492 






Drawings 


^1260 


Date 


Jan. 10-1901 


Corrections 


A. B.C. 


3Iachine 


12" Stop Valve 


Part of 


Chamber 






Pieces to 


3 


Pattern 




Corebojces 


2 






Castings 


One Bight. One Left 


Material 


Cast Iron 






Heniarks, 


Draa 


ing sJi Oil's right-hand. 


Change P 


ieces stored with Pattern 









Fig. 179. 



MARKING, RECORDING, AND STORING PATTERNS. 189 

tions and marked to correspond with the class let- 
ters on the pattern. 

When an order for castings from a pattern is 
completed in the foundry the man assigned to care 
for patterns should collect all pieces, core-boxes, 
etc., belonging to the pattern and clean them. Any 
repair needed should be done before the pattern is 
stored away. The pattern should then be stored 
in the section assigned to the class to which it 
belongs. When patterns are sent away to have 
castings made at a distant foundry the fact with 
any other necessary information can be noted on 
slips and filed with record-cards of the patterns in 
the card-rack — the slips to be removed from the 
card -rack when the patterns are returned. 



XXXI. 

SECTIONAL LINING IN MECHANICAL 
DRAWINGS. 

With the general use of blue-prints in place of 
tracings, as formerly used for mechanical working 
drawings, it becomes necessary to adopt some par- 
ticular marking when it is desired to designate the 
material to be employed. An effort is being made 
by the leading draughtsmen and technical journals 
to systematize the marking of mechanical drawings 
in this respect. Fig. i8o shows the markings most 

generally used at present. 

Z90 



SECTIONAL LINING IN MECHANICAL DRAIVINGS, 191 





1 

:^ 
.1 






If:;- 





^B 




^^H 








►^ 



00 

o 





0' 


^^^ 


I—" 


XVVV^VV^ 




^^ 






o 

o 



.•<s-t.-.?>:.--°4:.:;?i.-: 

-•*•»- Vs'i' •.••>>' y.v 








XXXII. 

• PRACTICAL GEOMETRY. 

^ A KNOWLEDGE of even the rudiments of geometry 
is of great assistance to pattern-makers. The fol- 
lowing geometrical problems, Figs. 1 81-19 2, are 
selected because of their more general practical ap- 
plication. If workmen will practice and familiarize 
themselves with their principles, they will add ma- 
terially to a knowledge that will greatly benefit them 
in laying off work. 

Fig. 181 illustrates the construction of a square on 
a given length of line. It also teaches how to erect 
a perpendicular on the line and at the end of it. 
Bisect the line ab, of given length; from the extrem- 
ities a and b describe the intersecting arcs c; a 
line drawn from c to the bisection of ab will be per- 
pendicular to the latter line. With one half the line 
ab as a radius, describe an arc from the point of 
bisection 0, intersecting the perpendicular at J; a 
line drawn from b through d will produce a diago- 
nal of the square. With the distance db as a ra- 
dius, from the point d describe an arc intersecting 
ab and the diagonal at c; a line drawn from this 
last intersection to a will be perpendicular to the 

192 



PRACTICAL GEOMETRY. 193 

line ah and equal to its length, thus completing 
two sides of the square. With the distance ah or 
ac from the points e and h describe the intersecting 
arcs /. Lines drawn from this intersection to h and 
e will complete the square. 

Fig. 182 shows how to describe an octagon in a 
given square. Construct the square as in Fig. 181. 
With one half of the diagonal as a radius, and from 
the points a, 6, e, /, describe arcs intersecting the 
sides of the square, as gh, etc.; lines connecting 
these intersections will produce the octagon. 

Fig. 183. To describe a hexagon in a circle. 
Draw center line and set off the diameter, ah. From 
a and h as centers, with distance ao and ho from 
a and 6, cut the circle at cm and en. Connect these 
points with lines to complete the hexagon. 

To describe a hexagon about a circle using Fig. i d>2^. 
Draw center line of indefinite length and set fg for 
diameter. With radius of describe an arc of circle 
from f to h with the radius; connect fh with line. 
Draw oh and extend indefinitely. Draw a tangent 
to the circle parallel with the line fh and intersecting 
radii at a and m. From as a center, with radius 
oa describe circle. From a and h as centers cut the 
circle with the radius and connect the intersections 
with lines as in the previous case. 

Fig. 184. To describe a regular polygon of any 
required number of sides. From point 0, with dis- 
tance oh, describe semicircle h and a, which divide 
into as many parts, a, c, d, e^ /, 6, as the polygon 
has sides. 



194 



THE ART OF PATTERN MAKING. 



e 


.' 


/ 


/ 


\ 




/ 






1 






/ 


\ 


c 


/ 


^\ 


>c 




^x 






\ 


' 




\ 


^jri 




^-•-''' 






/" 


1 ^\ 




/ 






/ 






/ 




^ 


/ 

/ 


1 \ \ 


\ 


/ 
/ 


1 ^ * 


\ 




1 s 


\ 

\ 




1 ^. / 



a 



yb 



e 9 f 


h 




a b 



Fig. 1 8 1. 



Fig. 182. 




\ 

\\ 

\ \ 
\ \ 
\ \ 
\ \ 
\ \ 
\ \ 
\ \ 

\ \ 

\ \ 
\ \ 
\ \ 
\ \ 


^ 


^^ \ ' 


\ 


^ ^ / 








^v \ / 


\ 


^•^id 


\ 






/ ^ ^^ 


\ 










/ \ 




/ \ 


N \ 


/ \ 




/ \ 


X \ 


/ 


\\ 


I — 


n\ 



Fig. 185. 



Fig. 186. 



PRACTICylL GEOMETRY. 



195 




Fig. 189. 



Fig. 190. 




Fig. 191. 



196 THE ART OF PATTERN-MAKING. 

Thus let a pentagon be required. From to the 
second point, d, draw od, and through the other 
points, e and /, draw lines extending indefinitely. 
Apply distance oh from b to h and from d to g. Con- 
nect these points. Or describe a circle intersect- 
ing obd, which will determine the points g and h. 

Fig. 185. To find the center of a triangle. Bi- 
sect the sides of the triangle, as a, b, c. From a, b, 
and c draw lines to the angle opposite each, inter- 
secting at d, the center. 

Fig. 186. To bisect inclination of two lines when 
point of intersection is inaccessible. Upon given 
lines ab and cd at any point draw perpendiculars 
eo and sr of equal lengths, and from o and 5 draw 
parallels to their respective lines intersecting at n. 
Bisect the angle ons, and connect mn with a line 
which will bisect the lines as required. 

Fig. 187. To find the center of radius of an arc. 
Divide. the arc into equal parts, as a, b, c. From a, 6, 
and c as centers, with a radius greater than 
their distance apart, describe intersecting arcs, as 
de and fg, both inside and outside of the arc. Draw 
lines through these intersections and extend them 
until they meet in the apex, as at h, which will be 
the center of the circle of which the arc is a 
part. 

Fig. 188. To describe a circular segment which 
will fill the angle between two diverging lines. Bi- 
sect the lines a, &, d, e by lines e, /, and connect per- 
pendiculars thereto to define the boundary of a 
segment to be described. Bisect angles at b and d 



PRACTICAL GEOMETRY. 197 

by lines intersecting at o, and from o, with radius 
oe, describe arc men. 

Fig. 189. To draw from or to the circumference 
of a circle lines leading to an inaccessible center. 
Divide the whole or any portion of the circum- 
ference into the desired number of equal parts, as 
a, h, c, and o\ then with any radius less than the 
distance of two divisions, describe intersecting arcs, 
as d, e, f. Draw lines from d to b, e to c, and /to 0, 
and they will lead to the center. 

Fig. 190. To draw a spiral about a given point. 
Assume c the center. Draw ab and divide into 
twice the number of parts that there are to be 
revolutions of line. From c describe the semi- 
circles d, e,f; bisect the distance between c and d at 
o, and from as a center describe semicircles g, h, i. 

Fig. 191. To describe an ellipse, approximately, by 
circular arcs. Draw major "axis gh and minor axis ik, 
set off their difference in length from o to a, and 
from Xo c draw line ac\ bisect its length and set off 
half from a to r ; draw rs parallel to ac. Set off on 
equal to or, and om equal to os ; from 5 and m draw 
lines through n and r, extending them indefinitely; 
from n and r as centers, with radius rh, draw the 
arcs dhf and bge\ from 5 and m as centers, with 
radius sf, draw the arcs ekf and bid. 

Note: This method is not satisfactory when the 
minor axis is less than two thirds of the major. 
An oval may be similarly described by circular 
arcs with any difference of major and minor 
axis. 



198 



THE ART OF PATTERN-MAKING. 



Fig. 192. To describe an ellipse to any length 
and breadth. Draw the major axis cd and minor 
axis ef\ from c and d as centers, with distance 
of half the major axis, describe arcs intersecting 
the major axis at h and i. Insert pins at h 
and i, and loop a string around them of such 
length that when a pencil is introduced within it 
will just reach to e or /. Bear upon the string and 
sweep around the center o, and an ellipse will be 
described. When an elliptograph is not available 
and the ellipse is to be constructed by points, the 
best and most accurate method of doing it is that 
shown by Fig. 193. 



7 8 
6^-1 — y— i;-- 



Id' 




--L I 

Fig. 193. 



Let DB be the major and AC the minor axis, 
intersecting at right angles at the center 0. With 
as a center and OC as a radius describe a circle. 
From the same center, with OD as a radius, describe 
another circle. Divide the larger circle into any 
number of equal parts, and from these intersections 



PRACTICAL GEOMETRY. I99 

draw radii which will also divide the inner circle 
correspondingly. From the points of intersection 
on the outer circle, as i, 2, 3, etc., draw lines parallel 
with the minor axis, and from the intersections on 
the inner circle, as i, 2, 3, etc., draw lines parallel 
with the major axis. The intersection of these 
lines, as at a, 6, c, etc., will determine the curve of 
the ellipse. 



XXXIII. 
SOME USEFUL RULES FOR THE SHOP. 

The following problems are frequently met with 
in the workshops of various trades, especially in 
pattern-making. They are readily solved with the 
aid of a few figures, and the rules for doing so are 
easily applied, and require no higher knowledge of 
mathematics than that of arithmetic. 

Probably the problem most frequently encoun- 
tered is to find the radius of an arc of a circle 
that will intersect three given points. (See Fig. 194.) 
It can be found by the following rule: Divide the 
square of half the chord by the versed sine, or 
height, and to the quotient add the versed sine. 
This sum will then equal the diameter. Example: 
Let the chord of the arc equal 60 inches and the 
versed sine 10 inches; required the radius. 

One half the chord 60/2 = 30 inches 

The square of half the chord. ... 30 X 30 = 900 inches 
Square of half -chord divided by 

versed sine 900/10 = 90 inches 

Diameter equals 90 -f 10 = 100 inches 

Radius equals 100/2 = 50 inches 

If it should be found inconvenient to describe 

the arc with trammels in consequence of the circle 

200 



SOME USEFUL RULES FOR THE SHOP, 

Fig. 194 



201 




Fig. 196. 



202 THE ART OF PATTERN-MAKING. 

being very large or the center inaccessible, it may 
be described as follows, when the chord of the arc 
and versed sine are determined : Drive a wire brad 
at each extremity of the chord and also at the end 
of the versed sine. Then provide two straight- 
edges ; the length of each must not be less than the 
lerigth of the chord. Let the straight-edges bear 
against the brads at the ends of the chord, and one 
end of each bear against the brad at the end of the 
versed sine. In this position secure the straight 
edges together. Now withdraw the brad at the 
end of the versed sine and insert a scriber in the 
apex of the angle formed by the straight-edges. By 
moving the templet to the right and left while bear- 
ing against the brads at the ends of the chord, the 
desired arc will be described. (Fig. 195.) 

When it is inconvenient to describe the arc by 
either of the foregoing methods, it may be arrived 
at by laying down the arc to a scale, erecting ordi- 
nates from the chord, and from the dimensions thus 
obtained develop to full size. The chord can be 
laid down full size, the ordinates erected from it, 
and with the aid of a batten intersecting their 
extremities the arc can be described. (Fig. 196.) 
But if greater accuracy is desired than is obtain- 
able by this method, the arc may be determined by 
computing the length of the ordinates. 

Let the diameter equal 304 feet. 

Let the chord equal 24 feet. 

In this case the first dimension to be found is the 
height of the versed sine, which is determined by 



SOME USEFUL RULES FOR THE SHOP. 293 

the following rule: Subtract the square of half 
the chord from the square of the radius and extract 
the square root of the difference ; subtract this root 
from the radius, and the remainder equals the versed 
sine. Example : 

Radius equals 304/2 = 152 feet 

Half -chord equals 24/2 = 12 feet 

152^—12^ = 23104—144 = 22960. ^22960 = 151.5256 
Versed sine = 152 — 151.5256 = .4744 feet. 

The versed sine being determined, the ordinates 
are found by the following rule : Locate the distance 
of the ordinates from the versed sine. Subtract 
the square of this distance from the square of the 
radius and extract the square root of the difference. 
Subtract the versed sine from the radius and then 
subtract this remainder from the root previously 
found, and the remainder is the required ordinate. 

The difference of the versed sine and radius will 
be a constant in finding all of the ordinates. 

As the distance from the versed sine is increased 
and the end of the chord is approached, accuracy is 
enhanced by diminishing the distance between the 
ordinates. Example: 

1522-23104 
4'= 16 

Diff. =23088 

\/23o88 = 151.9473 

152-. 4744 = 151. 5256 

151-9473- 151-5256 = .4217 ordinate. 



204 THE ART OF PATTERN-MAKING. 

Similarly the other ordinates are determined. 

\/i522-8'- 151.5256 = .2637 =Oj 



V1522- 10^-151.5256 = .1451 



\/i522- 11=^- 151.5256 = .0758 =03 
Vi52'-iii'- 151.5256 = .0387=0, 

Another problem frequently met with in laying 
off work is to form an offset; that is, to join two 
parallel lines with a compound curve either by 
employing two different radii or a similar radius 
for both sides. 

Having acquired the rule for computing the radius 
when the versed sine and chord of the arc are given, 
it becomes a simple matter for any one to compute the 
radii for this problem. In Fig. 197 it is required to 
have a uniform offset of three inches in a length of 
nine inches. The half -chord is one half of nine, 
or 4J inches, and the versed sine is one half the 
offset, or I J inches. The center line of offset must 
be joined first, and from the centers thus determined 
the outside curves are described. By the rule 
given. Fig. 194, the diameter = 4.571.5 -m. 5 = 15 
inches. Radius equals 15/2 =7^ inches. 

A peculiarity regarding this problem is that 
for like offsets the sum of the radii will always 
be equal, whether two similar or dissimilar radii 
are employed. For instance, it is shown (Fig. 197) 
that for an offset of three inches in nine, with 
similar radii of curvature, the sum of the radii is 15 



SOME USEFUL RULES FOR THE SHOP. 
Fig. 197. 



205 




Fig. 198. 



2o6 THE ART OF PATTERN-MAKING. 

inches. If it should be desired to have one radius 
twice as great as the other, it is only necessary to 
take I of 15, or 10, for one radius and J of 15, or 5, for 
the other (Fig. 198).* Or if it is desired to divide 
into : f and j, the radius will be respectively 1 1 J 
and 3|. This principle is graphically illustrated by 
Fig. 198. 

There are many other such problems as the fore- 
going that are frequently met with in laying off 
work, and for the solution of which the cut-and-try 
method is employed, when by the use of a little 
arithmetic, with a knowledge of the principles in- 
volved, a solution could be obtained more readily. 

Let it ibe required to cut a square out of a round 
stock, as in the case of a nut where a part of the 
length iS; cylindrical and a part square, the length 
of the sic^e of the square only being given. To find 
the dian|eter to turn the cylinder, the majority of 
workmen would lay down the square and measure 
across the corners; but it can be computed more 
readily by the following rule : Multiply the length of 
side by 1.4 142, and the product is the distance 
across the corners, or the diameter of the circum- 
scribing circle. Example: The side of a square is 
3 inches ; required the diameter of the circumscribing 
circle. 

3X1.4142=4.2426 inches. (See Fig. 199.) 

If, instead of a square, it is desired to find the 
circumscribing circle of a hexagon, use the following 
rule: Multiply the distance across the sides by 
I.I 547. Example: The distance across the sides of 



SOME USEFUL RULES FOR THE SHOP, 207 

a hexagon is 3 inches; required the diameter of 
the circumscribing circle. 

3X1.1547=3.4641 inches. (Fig. 200.) 

To find the circumscribing circle of an octagon, 
multiply the distance across the sides by 1.0824. 
Example: The distance across the sides of an octa- 
gon being 3 inches, required the diameter of the 
circumscribing circle. 

3X1.0824 = 3.2472 inches. (Fig. 201.) 

A problem of common occurrence is to divide 
a given length into a number of equal parts, each 
part being separated by some object, as a rib or 
bracket. (Fig. 202.) 

The usual way of working out this is to repeatedly 
try until the desired spacing is accomplished. I 
have found the following to be a convenient way 
of arriving at the proper spacing when the ribs are 
of uniform thickness. From the entire length sub- 
tract the thickness of one of the ribs and divide the 
remainder by the number of spaces, and the quo- 
tient will be equal to a space and a rib. With this 
distance begin at the inside edge of one of the ribs, 
as at a, and step off, terminating at the outside 
edge of the rib at the opposite end, as h. Then 
reverse this operation, beginning at c and terminat- 
ing at d. 

Example : A length of 90 inches, having five ribs 
2 inches thick, is required to be divided into four 
parts and the ribs to be of equal distance apart. 

90-2=88 

88/4 = 22 =the distance to step off with. 



2o8 



THE ART OF PATTERN-MAKING, 



Of the various methods of constructing right 
angles without the aid of a square, the two following 
are the most convenient (Fig. 203). A triangle hav- 
ing its sides 3, 4, and 5 in length, or in this proportion, 
has one angle at right angles. Lay off AB equal to a 




Fig. 200. 



Fig. 201. 



length of 4. With a length of 5 and with one point 
of the dividers at A describe an arc. With a length 
of 3 and with one point of the dividers at B describe 
another arc at C, Draw right lines from the inter- 
sections of the arcs to A and B. The triangle thus 
formed will have one right angle. 



SOME USEFUL RULES FOR THE SHOP. 



209 



An angle circumscribed by a semicircle is a right 
angle (Fig. 204). Draw the line AB. Set a pair 
of dividers to any convenient distance and, with one 
point above the line, describe a semicircle inter- 
secting the point B and the line between A and B ; 
draw a line from this last intersection through the 
center intersecting the opposite side of the semi- 

FiG. 202. 



&L— 



-20- 



-20- 



t 



90- 



i ■ 



-22- 



22 



•20- 



-20- 



-22. — 



j^ 22— — ->}< 23—^ — ->< 22 




■22 ->i |« 

00 .._>4 



*^c 



./ 



..A ! 



k\/ 



'B 



Fig. 203. Fig. 204. 

circle at C\ draw a right line from C to B, and the 
angle thus formed will be a right angle. 

To find the weight, length, or area of castings of 
the different metals in ordinary use. 
Let A = area ; 
L = length ; 
W = weight ; 
C= weight of a cubic inch of metal. 



2 10 



THE ART OF PATTERN-MAKING. 



^ = .0926 for cast aluminum; 



C = .2482 


zinc ; 


^==.2607 


" iron; 


C = .284 " 


'* steel; 


C = .293 


*' brass; 


<^ = -3i65 " 


" bronze gun-metal; 


<^ = -3i79 '* 


" copper; 


C=.4io6 


*' lead; 



Example: Required the weight of cast iron, 24 
inches long, 2 inches in diameter; its length, and 
weight per cubic inch; its area. 

ylXLxC=W = 3.i4i6X24X.26o7 = i9.656, wt. 

W . 19.656 



LXC 

W 

AXC 

W 



= A 



L = 



24X.2607 
19.656 



3.1416 X.2607 



= 3.1416 sq. inches, area. 
= 24 in. long. 



AXL 



T=G 



^^-^ — — = .2607, wt. cubic inch. 

3. 1416X24 : ' 



To find the approximate weight of casting from 
weight of pattern. 

The average weight of a cubic inch of the pine 
lumber used for patterns is about .015 pound. 

.2607 



Then cast iron is 



•015 



or 17.38 times heavier 



than the pine. 

When a pattern does not contain cores, or where 
due allowance is made for cores and core-prints, 
an approximation of the weight of a casting may 
be arrived at by weighing the pattern and multi- 



SOME USEFUL RULES FOR THE SHOP, 211 

plying its weight by the following tabular number 
according to the metal required: 

Cast aluminum 5 ^ ^ 

zinc 

iron _ 

steel 

brass 

bronze, G. M 



16.5 

17.38 
18.9 

19.33 
21 .1 



copper 21.2 

lead 

27.37 



XXXIV. 

HANDY TOOLS FOR PATTERN-MAKERS. 

Figs. 205-208 show several handy devices for 
pattern-makers which, while they are not new, 
should be better known and more generally used. 

Fig. 205 shows three views of the centering-plate, 
which is very convenient when describing a semi- 
circle from a center situated on the edge of the work. 
It is made of brass about one-sixteenth inch thick. 
The semicircles a and b can be respectively about 
one and a half inches and one-half inch diameter, and 
should have their edges bevelled to allow the indi- 
cator marks to come close to the center line on the 
work. The apron, c, is about one-half inch wide and 
one-eighth thick. It projects perpendicularly from 
the under side of the plate and is the division be- 
tween the two semicircles. The centers d and e 
for the divider-point are located over the edges of 
the apron. A line is scribed on the plate at right 
angles to the apron, passing through the two centers 
and extending to edges of the semicircles. 

Fig. 206 represents the plate in use. A center 

line is scribed on the piece of work. The plate is 

held by one hand and adjusted to make the apron 

212 



HANDY TOOLS FOR PATTERN-MAKERS. 213 

bear against the edge of the piece of work, and the 
indicator mark on the edge of the semicircle to 
match the center Une on the work. 

The large semicircle is applied for circles larger 
than its diameter, and the smaller for circles between 
the two diameters on the plate. 

Fig. 207 shows a simple and excellent little tool 
for rounding the corners of patterns, a is a longi- 
tudinal section, h a view of the working face, and 
c a section on the line de. It is advisable to have 
about three of these tools, one for an eighth, one 
for a quarter, and one for three-eighths radius. The 
cutter, which is illustrated full size for quarter inch, 
is made of steel, about two and a half inches, 
and including the handle, about five inches long. 
Pattern-makers using these tools appreciate their 
value. 

Fig. 208 shows a convenient device for obtaining 
the radii and laying off segments, a is a plan, and h 
a section. As illustrated it is intended for sixths 
of a circle, or a 60-degree angle. A brass plate hav- 
ing a small hole is fitted at the apex of an angle. 
The hole is intended for a center in setting the 
trammels, and is situated about one- tenth inch from 
the inside of the angle, to allow for fitting on the 
ends of the segments. Beginning at the center of 
the hole, one side of the triangle is graduated and 
marked in inches and fractions of an inch. 

There should be several of these angles kept in 
a convenient place for the use of the shop. One 
should be for quarters, or 90 degrees. Two sizes 



HANDY TOOLS FOR PATTERN-MAKERS. 215 

are necessary for sixths, or 60 degrees; one ad- 
mitting of 15 inches and one of 30 inches radius. 
The one for eighths, or 45 degrees, should admit of 
a radius of at least 36 inches. 

When preparing for a job of segment work it is 
the common practice to make a pattern to mark 
off the segments by. In using this segment gauge, 
as it may be called, the width of the piece intended 
for the pattern is immaterial if it is of sufficient size 
for the segment. It is simply necessary to secure 
the gauge to the piece of board, and the center of the 
circle will at the same time be located. The trammel 
can then be set by the graduations on the side of 
the triangle, the segment scribed, and its ends 
marked at the insides of the triangle. 



XXXV. 

METHOD OF MAKING SPECIAL SHRINKAGE 

RULES. 



Pattern-makers sometimes require a special 
shrinkage rule that is not usually made or to be 
found for sale. 

Figs. 209, 210 show a method of making such a 
rule by hand graduation, which when expertly done 
will give entire satisfaction. 



U.S. STANDARD 

ll .31 .3 




Fig, 209. 

Secure a U. S. standard rule to a board so as to 

have the upper surface clear. Select a suitable 

piece of wood, preferably box, beech, or maple, 

make the piece perfectly straight, of the same 

thickness as the standard and somewhat longer 

than the required finished length. 

Lay off from the end of the standard rule the 

216 



MAKING SPECIAL SHRINK AGE RULES, 217 

additional length for the particular purpose re- 
quired. With the radius AB, and one point of 
the trammel at A^ describe an arc intersecting a 
line drawn at right angles from the end of the 
standard rule at C. Secure the blank to the board 
with its inner edge intersecting the points A and C. 
Make a gauge, D, of thin sheet steel with a guide 
flange turned down to bear against the outer edge 
of the blank. 

The marking-tool should be thin and sharp and 
held in the same position during the graduation. A 
great deal depends upon this to secure accuracy. 



XXXVI. 
A HANDY STRAIGHT-EDGE FOR MARKING. 

When truing up a surface with a bench-plane it is 
the usual custom to use a straight-edge coated with 
chalk or some colored material, to mark the high 
places on the board. This substance is soon worn 
off by the repeated use of the straight-edge and 
consequently requires frequent renewal. 

Fig. 2IO shows a convenient device which obvi- 
ates the use of chalk, etc., and is always ready for 
marking when wanted. A convenient size for this 
device is twenty-four inches long, three inches wide, 



s 



8 



Fig. 2IO. 
and the thickness made of two pieces of wood, one 
five eighths and the other three eighths of an inch 
thick. The thicker piece is rabbeted to receive a 
strip of sheet lead about two inches wide and one 
eighth of an inch thick, the lead being allowed to 
project outside of the wood about one-quarter inch. 
The two pieces are fastened together with screws 
to hold the lead firmly in place. The lead is easily 
kept straight by passing an iron plane over it occa- 
sionally. 

218 



XXXVII. 
FILING HAND-SAWS. 

The hand-saw is one of the most important of 
pattern-makers' tools, as it is of all other workers in 
wood, and it is one of the most difficult of their tools 
to put in good order. Many excellent mechanics 
are not able properly to file a hand-saw without 
some device to aid them. 

Fig. 211 shows an appliance that will not only be 
a help to the expert when filing saws, but will make 
it almost impossible for the novice to go wrong when 
intelligently applied. A, B, and C show a saw- 
clamp, which can be of any kind. It is provided 
with a shelf, a, extending from the back and at right 
angles with the blade of the saw. A piece of glass, 
6, preferably about a quarter of an inch thick, is 
secured to the shelf in such a manner as to be easily 
raised. 

Three sheets of paper about the size of the glass 

are prepared with heavy lines so that the lines can 

be plainly seen when placed under the glass. One 

sheet has the lines at right angles to the saw-blade, to 

be used when filing rip- or band-saws. Two sheets 

have the lines at an angle, one extending to the 

219 



220 



THE ART OF PATTERN-MAKING. 



right and one to the left, according to the bevel it 
is desired to have the teeth for cross-cutting. 

D, the file, which is shown on a larger scale, is 




B 





z 



\ 

a 



Fig. 2 11. 
prepared by driving its point into a small block, c, 
about three by one by a half inch. The lower 
edge of the block is to rest on the glass and is 
slightly rounded. The position of the comer of the 
file to be used with reference to the curved edge of 
the block determines the rake of the teeth. 



FILING HAND-SAIVS, 221 

When prepared for use the sheet whose hnes are 
required is exposed under the glass. The file with 
the curved edge of the block resting on the glass is to 
follow the lines when filing. Except when the teeth 
are very large it is well not to lift the block from 
the glass, but pass the file to the next tooth by 
raising the handle sufficiently. 



XXXVIII. 



WAX FILLETS. 



Fig 212 shows handy devices for making and 
applying wax fillets. A represents a press made of 
three-quarter-inch brass tube about five inches 
long; one end of the tube is securely closed by a 
wooden plug. A plunger made of close-grained 
hard wood is made to work in the tube ; the fit should 
be as nearly air-tight as possible to make the plunger. 
A hole is made through the side of the tube close to 
the inner end of the plug. The diameter of the hole 
will be according to the size of the fillet desired; a 
diameter of one-sixteenth inch is suitable for quar- 
ter-inch fillets. 



BRASS TUBE 






212. 



To make the fillet stock, beeswax is placed in the 
tube, and pressure applied on the end of the plunger, 
which will cause the wax to issue from the hole in an 



222 



H^AX FILLETS, 223 

unbroken thread; this can be coiled and preserved 
for future use.' The pressure can be applied by 
placing the ends of the press between the jaws of a 
hand-screw or bench-vise. B shows a tool, to be 
found on the market, made for forming wax fillets. 
The wax being placed in the desired corner, the 
tool, which has been heated in hot water, is applied 
and moved along the wax with sufficient pressure 
with the result that a neat and quick fillet is formed 
where a wood or leather fillet would be difficult. In 
the absence of the above tool, one can be improvised 
by grinding the end of a wire nail or a piece of wire 
to the required form. 



XXXIX. 

INSERTING WOOD-SCREWS INTO END 
GRAINS OF WOOD. 

Wood-screws inserted into the end grains, espe- 
cially of soft wood, do not take a very strong hold, 
but the hold may be increased by backing out the 




Fig. 213. 

screw after being inserted and placing a small 
amount of glue in the hole and then reinserting the 

224 



IVOOD-SCREIVS IN END GRAINS OF IVOOD. 225 

screw. When screws are to be taken out and 
reinserted into end-grain wood, as is often necessary 
where work is required to be taken apart in the 
foundry, simply screwing them into the end grain 
should not be depended upon, but a plug of hard 
wood should be inserted into the work and the screw 
allowed to pass through it at right angles to the 
grain of the plug (see Fig. 213). When the screw will 
no longer hold in consequence of its repeated with- 
drawals, the worn-out plug may be taken out and 
a new plug inserted. 



XL. 

BOARD MEASURE. 

In board measure all boards are assumed to be 
one inch thick. When all dimensions are in feet — 
Rule: Multiply length by breadth, and product will 
give surface in square feet. Example: Required 
the feet, B. M., in a board i6 ft. long, 1.25 ft. wide, 
and one inch thick. 

16X1. 25 =20 feet. 

When either dimension is in feet — Rule : Multiply 
length by breadth, and the product by the thickness, 
and then divide by 12. Example: Required the 
feet, B. M., in a board 16 feet long, 15 inches wide, 
and I J inches thick. 

16X15X1.5=360, and 3604-12=30 ft. 

When all dimensions are in inches proceed as 

before and divide by 144. Six inches and over are 

counted an additional foot. 

226 



XLI. 

TO COMPUTE VOLUME OF SQUARED 
TIMBER. 

When all dimensions are in feet — Rule: Multiply 
length, breadth, and thickness together and product 
will give volume in cubic feet. Example: A piece 
of timber is 1.25 feet square and 20 feet long. Re- 
quired its volume: 

1. 25X1. 25X20' = 31. 25 cubic feet. 

When either dimension is in feet proceed as 
before and divide by 144. Example: 

15" X 15" X 20' ^ .. 

-^ "^ =31.25 cu. ft. 

144 

When all dimensions are in inches proceed as 
before and divide by 1728. Example: 

15' ' X 15^^X240^^ ^ .^ 

^ - = 31.25 cu. ft. 

1728 ^ ^ 

Allowance is to be made for bark by deducting 
from each girth from .5 inch in logs with thin 
bark to 2 inches in logs with thick bark. 

To reduce to board measure multiply cubic feet 
by 12, thus: 31.25X12=375 feet B. M. 

Lineal feet is the length regardless of breadth 

and thickness. 

227 



XLII. 

TIMBER MEASURE. 

To compute the volume of round timber inside of 
bark. When all dimensions are in feet — Rule: 
Add together the squares of the greater and lesser 
ends, and the product of the two diameters. Mul- 
tiply the sum by .7854 and that product by one third 
of the length. 

Example: A piece of timber, barked, is 15 feet 
long. The diameters of the ends are 2 and 1.5 feet. 
Required the volume. 

2^+1.5^ + 2X1.5=9.25, which, multiplied by 

.7854, and that product by — = 36.3247 cubic feet. 

When all dimensions are in inches proceed as 
before and divide by 1728. 

To compute the square that a round log will cut. 
Rule: Divide the diameter of the small end inside 
of bark by 1.4 142, and the quotient will equal the 
side of the square. 

Example : A log is 14.5 inches in diameter at small 
end. Required the side when square. 

- — ^— ^=io.2S^ inches. 
1. 4142 ^ 

Or multiply diameter by 0.7071. 

Thus 14.5 X. 7071 =10.253 inches, the length of 

the side of square. 

228 



xLiir. 

STRENGTH AND WEIGHT OF WOODS. 



The strength and weight of the same kind of 
wood will vary considerably; this variation is 
caused by the conditions under which it grows, 
is prepared and seasoned. The following table, 
compiled from different authorities and the author's 
own experiments, exhibits a fair average for sound 
well-seasoned timber of the kinds given : 



Kind of Wood. 



Average 
Tensile 

Strength 

per Sq. Inch, 

in Lbs. 



Average 

Crushing 

Strength 

pei" Sq. Inch 

in Lbs. 



Average 

Weight per 

Cubic Ft., 

in Lbs. 



Ash, American 

Beech 

Cedar 

Cherry 

Chestnut 

Cork 

Cypress 

Hickory 

Mahogany, hard .... 

soft 

Oak, American white 

" EngHsh 

" Uve, Ala 

" upland 

Pine, Southern Ga.. . 

" white 

" white Mich. . . . 

" yellow long leaf. 

Poplar, yellow 

Redwood, Pac. Coast. 

Spruce. 

Walnut, red , 

black 



16,000 
18,000 
10,300 
12,500 
12,500 

6,000 
18,000 
20,000 

8,000 
18,000 
19,000 
16,400 
10,000 
10,000 
11,000 

19,000 
7,000 
10,000 
1 1,000 
17,000 



5,800 
6,900 
6,000 

5,300 



8,900 
8,800 

9,000 
10,000 
7,700 
6,800 
8,900 



8,000 

6,000 
6,800 



38 
40 

35 
41 
39 
15 

27 

53 
53 
35 
50 

55 
60 
42 

45 
28 
26 
42 

31 
24 
29 
39 

37 



229 



XLIV. 



MISCELLANEOUS TABLES, ETC. 



TABLE OF DECIMAL^ EQUIVALKNTS OF MILLIMETERS 
AND FRACTIONS OF MILLIMETERS. 

I /lOo mm. = .0003937". 



Mm. 


Inches. 


Mm. 


Inches. 


Mm. 


Inches. 


1/50 = 


.00079 


26/50 = 


.02047 


2 = 


•07874 


2/50 = 


.00157 


27/50 = 


.02126 


3 = 


.I1811 


3/50 = 


.00236 


28/50 = 


.02205 


4 = 


•15748 


4/50 = 


■0031 5 


29/50 = 


.02283 


5 = 


.19685 


5/50 = 


•00394 


30/50 = 


.02362 


6 = 


.23622 


6/50 = 


.00472 


31/50 = 


.02441 


7 = 


•27559 


7/50= 


•00551 


32/50= 


.02520 


8 = 


.31496 


8/50= 


. 00630 


33/50 = 


.02598 


9 = 


• 35433 


9/50 = 


. 00709 


34/50 = 


.02677 


10= 


.39370 


10/50 = 


.00787 


35/50 = 


.02756 


11 = 


• 43307 


11/50 = 


.00866 


36/50 = 


.02835 


12 = 


•47244 


12/50 = 


•00945 


37/50 = 


•02913 


13 = 


.51181 


13/50= 


.01024 


38/50 = 


.02992 


14 = 


•55118 


14/50 = 


.01102 


39/50 = 


.03071 


15 = 


.59055 


15/50= 


.01181 


40/50 = 


•03150 


16 = 


.62992 


16/50= 


.01260 


41/50 = 


.03228 


17 = 


.66929 


17/50= 


•01339 


42/50 = 


• 03307 


18 = 


. 70866 


18/50 = 


.01417 


43/50 = 


.03386 


19 = 


. 74803 


19/50 = 


.01496 


44/50 = 


•03465 


20= 


.78740 


20/50 = 


•01575 


45/50 = 


•03543 


21 = 


.82677 


21/50 = 


01654 


46/50 = 


.03622 


22 = 


.86614 


22/50 = 


.01732 


47/50 = 


.03701 


23 = 


.90551 


23/50 = 


.01811 


48/50= 


.03780 


24= 


.94488 


24/50= 


.01890 


49/50= 


•03858 


25 = 


.98425 


25/50 = 


.01969 


1 = 


•03937 


26=1 


.02362 



10 mm. = I centimeter =0.3937 inches. 
10 cm. = I decimeter =3.937 " 
10 dm. = I meter =39^37 ** 

25.4 mm. = I English inch. 



230 



MISCELLANEOUS TABLES, ETC. 



231 



TABLE OF DECIMAL EQUIVALENTvS OF 8ths, i6ths, 
32DS, AND 64THS OF AN INCH. 



8ths. 


9/32= .28125 ■ 


19/64=. 296875 


i/8=.i25 


11/32 = 


34375 


21/64 = 


328125 


1/4= .250 


13/32 = 


40625 


23/64= 


359375 


3/8=. 375 


15/32 = 


46875 


25/64= 


390625 


1/2= .500 


17/32 = 


53125 


27/64= 


421875 


5/8=. 625 


19/32 = 


59375 


29/64= 


453125 


3/4=. 750 


21/32 = 


65625 


31/64= 


484375 


7/8=. 875 


23/32 = 


71875 


33/64= 


515625 


i6ths. 


25/32 = 


78125 


35/64 = 


546875 




27/32 = 


84375 


37/64 = 


578125 


I /i6= "^ '^ '' 
3/16 = 
5/16 = 

mm t ^ C 


1875 
3125 


29/32 = 


90625 


39/64 = 


609375 


31/32= .96875 


41/64 = 
43/64= 


640625 
671875 


7/16= 

9/16= 

11/16= 

13/16= 

T r /t A 


4375 
5625 

6875 
8125 


64ths. 
1/64= .015625 


45/64 = 
47/64 = 


703125 
734375 


3/64= .046875 
5/64= .078125 


49/64= 
51/64 = 


765625 
796875 


I5/I6— .y^/0 


7/64= . 109375 


53/64 = 


828125 


32ds. 


9/64= . 140625 


55/64 = 


859375 


1/32= .03125 


11/64= .171875 


57/64 = 


890625 


3/32= .09375 


13/64= .203125 


59/64 = 


921875 


5/32= .15625 


15/64= .234375 


61/64 = 


953125 


7/32=. 21875 


17/64= .265625 


63/64= .984375 



TRIGONOMETRICAL EXPRESSIONS. 
The diagram shows the different trigonometrical expressions in 
terms of the angle A. 





^ COTANGENT A 


.__.J 


< 

z 
5 

c 




.^ COSINE A ^>V 


• 

0' y- 


r \ 

N 


/// z 


\ z 

\ UJ 

\ Z 
\ < 
\ 1- 

VERSINE 






J- r*» rMi in JWj 








• 








Fig. 214. 
Complement of an angle = its difference from 90°. 
Supplement , . . . = its difference from 180°. 



232 THE ART OF PATTERN-MAKING. 

MENSURATION OF vSURFACES. 

Area of circle = Diameter^ X.7S54 

Area of ellipse =Transv. axisXconjug. axisX.7854 

Area of sector of circle = Arc X ^ radius 

Area of parabola =Base Xf height 

Surface of sphere = Diameter^ X 3. 14 16 

MENSURATION OF SOLIDS. 

Cylinder =Area of one end X length 

Sphere = Diameter^ X.5236 

Cone, or pyramid = Area of base Xi height 

Any prismoid =Suni of areas of the two parallel surfaces 
+ 4 times the area of a midway section 
X length, and the total product divided by 6. 



STEEL-WIRE FINISHING-NAILS SUITABLE FOR PATTERN 

WORK. 

The gauge is that of the American Steel and Wire Co. 



Size. 


Length. 


Gauge. 


Approximate 
No. to Lb. 


Diameter in 
Decim. of Inch. 




f inch 


No. 20 


14240 


.035 




h " 


" 20 


8112 


.035 




f " 


" 19 


4848 


.041 




f " 


" 18 


2928 


.047 




7 " 


" 18 


2510 


.047 


2d 


I " 


" 16^ 


1351 


.058 


3d 


li " 


" i5i 


807 


.067 


4d 


U " 


" 15 


584 


.072 


5d 


If " 


" 15 


500 


.072 


6d 


2 " 


" i3i 


309 


.086 


yd 


2i " 


" 13 


238 


.092 


8d 


2h " 


" 12^ 


189 


.098 


9d 


2f " 


" 12^ 


172 


.098 


lod 


3 " 


" Hi 


121 


.112 


i2d 


3i " 


" Hi 


"3 


.112 


i6d 


3h " 


" II 


90 


.120 


2od 


4 " 


" 10 


62 


.135 



MISCELLANEOUS TABLES, ETC. 

STEEL-WIRE COMMON NAILS. 



233 





Size. 


Length. 


Gauge . 


Approx. No. to Lb. 




2d 


I inch 


No. 15 


876 




3ci 


li ' 






' 14 


568 




4d 


i^ ' 






' iH 


316 




5cl 


If ' 






' I2i 


271 




6d 


2 ' 






' 11^ 


181 




7d 


2i ' 






' "i 


161 




8d 


2i ' 






' lOi 


106 




9d 


2! ' 






' loi 


96 




lod 


3 ' 






' 9 


69 




i2d 


2>\ ' 






' 9 


63 




i6d 


3h ' 






' 8 


49 




2od 


4 ' 






' 6 


31 




3od 


4i ' 






' 5 


24 




4od 


5 ' 






' 4 


18 




5od 


5i ' 






' 3 


14 




6od 


6 ' 






' 2 


II 



XLV. 
STANDARD WOOD-SCREWS. 

Wood-screws are very familiar and indispensable 
articles with pattern-makers, but it is doubtful if 
there is one in a hundred that could state the 
angle of the head if asked the question. The angle 
being 41 degrees, or the sides having a subtended 
angle of 82 degrees, accounts for the fact that 
the ordinary commercial countersinks which com- 
monly have an included angle of 60 or 90 degrees 
are never just right for the heads of wood-screws. 

Messrs. Asa S. Cook & Co., manufacturers of 
machinery for making wood-screws, have furnished 
the following table of data regarding the chief 
features of wood-screws as used by all of the princi- 
pal makers of them in the United States. 

234 



STANDARD IVOOD-SCREIVS. 



235 



U. S. STANDARD WOOD-SCREWS REDUCED TO 

THOUSANDTHS. 

Body, also Flat and Round Heads. 



Body. 


Flat-head Dia. (Corner). 


Round-head. 


No. 


Diameter. 


Sharp. 


Round. 


Diameter. 


Depth. 





.05784 


. II 


. 10968 


. 106 


.042 


I 


.071 


.136 


•1356 


.130125 


.051 


2 


.08416 


.162 


.16152 


.15425 


.06 


3 


.09732 


.188 


.18744 


.178375 


.069 


4 


.11048 


.214 


.21336 


.2025 


.078 


5 


.12364 


.24 


.23928 


.226625 


.087 


6 


.1368 


.266 


.2652 


.25075 


.096 


7 


• 14996 


.292 


.29112 


.274875 


.105 


8 


.16312 


.318 


.31704 


.299 


.114 


9 


.17628 


.344 


.34296 


.323125 


.123 


10 


.18944 


.37 


.36888 


.34725 


.132 


II 


.2026 


•396 


.3948 


.371375 


.141 


12 


.21576 


.422 


.42072 


.3955 


•15 


13 


.22892 


.448 


. 44664 


.419625 


•159 


14 


. 24208 


.474 


•47256 


.44375 


.168 


15 


.25524 


.5 


.49848 


.467875 


.177 


16 


.2684 


.526 


■5244 


•492 


.186 


17 


.28156 


.552 


.55032 


.516125 


•195 


18 


.29472 


.578 


.57624 


•54025 


.204 


19 


.30788 


.604 


.60216 


•564375 


.213 


20 


.32104 


.63 


.62808 


•5885 


.222 


21 


.3342 


.656 


• 654 


.612625 


• 231 


22 


.34736 


.682 


.67992 


•63675 


•24 


23 


.36052 


.708 


• 70584 


.660875 


.249 


24 


.37368 


•734 


.73176 


.685 


.258 


25 


.38684 


.76 


.75768 


.709125 


.267 


26 


.4 


.786 


.7836 


•73325 


.276 


27 


.41316 


.812 


.80952 


•757375 


.285 


28 


.42632 


.838 


.83544 


.7815 


.294 


29 


•43948 


.864 


.86136 


.805625 


.303 


30 


.45264 


.89 


.88728 


.82975 


.312 


Ratio 


.01316 


.026 


.02592 


.024125 


.009 



T 1 A ^'^"^^^t'o^ Flat heads. 
Included angle 82° ) 

Length of thread is 7/10 of whole length of screw. Round heads, 

length measured from under head. 

formula for wood-screws. 
iV = number ; D = diameter. 

(D-.056) 



DHNX .01325)+ .056 N = 



.01325 



XLVI. 

HOW TO APPROXIMATE THE WEIGHT OF 
AN IRON CASTING FROM ITS OBSERVA- 
TION. 

It occasionally happens that an approximate 
weight of a casting is desired where little or no 
opportunity is offered for measurements, and 
where simple observation of the pattern or casting 
is all that is available for data. 

By remembering that a cubic foot of cast iron 
weighs 450 pounds, a square foot one inch thick 
37.5 pounds, and 3.84 cubic inches weigh one 
pound, together with a little practice in judging 
dimensions, a fairly offhand, rough estimate can 
be made as follows: Judge the dimensions of pat- 
tern or casting and mentally estimate the cubical 
or superficial contents, then mentally multiply 
that by one of the above quantities accordingly as 
the case requires. For instance required the 
weight of a casting judged to be 10 by 5 feet and 
2 inches thick. It will require very little mental 

exercise to determine that these dimensions will 

236 



APPROXIMATE IV EIGHT OF AN IRON CASTING. 237 

equal 100 square feet one inch thick, which, multi- 
phed by 37.5, will equal 3750 pounds. By the 
same process of reasoning the weights for other 
metals can be determined by fixing in mind the 
necessary data for the metals. That for steel 
castings is 490 pounds per cubic foot, 40.86 poimds 
per square foot, and 3.522, or, roughly, 3.5 cubic 
inches per pound. But by far the most frequent 
occasion for this exercise will be for cast iron. 
The following tables are convenient for determining 
the length of bar of the different metals com- 
monly used for weights. 

TABLE I, GIVING WEIGHT PER INCH IN LENGTH OF 
ROUND BARS FROM V TO 3" DIAM. 



Diam. 


Cast Iron. 


Cast Brass. 


Cast Lead. 


Cast Steel. 


I inch 


.2042 


.2301 


.322 


.2228 


H " 


.2584 




2912 


.4075 


.2821 


li " 


•319 




3595 


.503 


.3482 


If " 


.3858 




4348 


.6084 


.4214 


li " 


•4594 




5179 


•7244 


•5015 


If " 


.5389 




6073 


.8499 


.5885 


If " 


.6253 




7046 


.986 


.6526 


i| " 


.7178 




8089 


I. 132 


.7836 


2 " 


.8166 




9203 


1.288 


.8916 


2i " 


.9219 




0389 


1-4538 


I .0065 


2i " 


I .0337 




1649 


I. 6301 


I. 1 284 


2| " 


1.1518 




2979 


I. 8163 


1.2573 


2i " 


1 . 276 




438 


2 .0122 


1.3931 


2| " 


I . 4068 




5854 


2.2185 


1.5359 


2f " 


I -5441 




7401 


2 . 435 


1.6856 


2i " 


1.6876 




9018 


2 .6613 


1.8423 


3 " 


1.8376 


2 


0709 


2.8978 


2 . 006 I 



238 



THE ^RT OF PATTERN MAKING. 



TABLE II, GIVING WEIGHT PER INCH IN LENGTH OF 
SQUARE BARS, FROM V TO 3" SQUARE. 



Side of Square. 


Cast Iron. 


Cast Brass. 


Cast Lead. 


Cast Steel. 


I inch 


.26 


•293 


.41 


.2838 


li " 


•329 


.37 


•519 




3591 


i\ " 


.406 


•457 


.64 




4434 


If " 


.491 


•554 


•775 




5365 


H " 


.585 


.659 


.922 




6385 


i| " 


.686 


.773 


1.082 




7494 


If " 


.796 


.897 


1.255 




8691 


li " 


.914 


1.03 


1. 441 




9977 


2 " 


1 .04 


1 . 1 72 


1 .64 




1352 


2i " 


1. 174 


1-323 


1. 851 




2815 


2i " 


1. 316 


1.483 


2.075 




4367 


2| " 


1 .466 


1.652 


2.312 




6008 


2i " 


1.625 


1. 831 


2 . 562 




7737 


2f " 


I. 791 


2.018 


2.825 




9555 


2f " 


1 .966 


2.215 


3.100 


2 


1462 


2i " 


2.149 


2.491 


3.389 


2 


3457 


3 " 


2.34 


2.637 


3.69 


2.5542 



Rule: Divide the given weight by the tabular 
number corresponding to the size of the bar and 
required metal. 

Example: Required the length of a 20-lb. cast- 
iron weight of if diameter: lbs. ^ tab. number 
equals 20^.7178, equals 27.86 inches long. 

Required the length of a 20-lb. cast lead weight 
of if side of square. 20 -^ 1.082 = 18.48 inches. 



AREAS OF CIRCLES, ETC. 



239 



AREAS OF CIRCLES, AND LENGTHS OF THE SIDES OF 
SQUARES OF THE SAME AREA. 



Diam. of 


Area of Circle 


Sides of Sq. 


Diam. of 


Area of Circle 


Sides of Sq 


Circle in 


in Square 


of Same 


Circle in 


in Square 


of Same 


Inches. 


Inches. 


Area in 


Inches. 


Inches. 


Area in 






Sq. Ins. 






Sq. Ins. 


I 


.785 


.89 


21^ 


363.05 


19.05 


I^ 


1.767 


1-33 


22 


380.13 


19.50 


2 


3-142 


1.77 


22i 


397-61 


19.94 


2^ 


4.909 


2.22 


23 


415.48 


20.38 


3 


7.069 


2.66 


23i 


433.74 


20.83 


3i 


9.621 


3.10 


24 


452.39 


21 . 27 


4 


12.566 


3.54 


24i ' 


471.44 


21.71 


4^ 


15 904 


3-99 


25 


490.88 


22. 16 


5 


19 635 


4-43 


25§ 


510.71 


22.60 


5^ 


23.758 


4.87 


26 


530.93 


23.04 


6 


28.274 


5.32 


26I 


551-55 


23.49 


6i 


33-183 


5.76 


27 


572.56 


23.93 


7 


38.485 


6. 20 


27i 


593 96 


24-37 


Ih 


44-179 


6.65 


28 


615-75 


24.81 


8 


50.266 


7.09 


2^ 


637 -94 


25 .26 


8^ 


56.745 


7.53 


29 


660.52 


25.70 


9 


63.617 


7.98 


29^ 


683.49 


26. 14 


9^ 


70.882 


8.42 


30 


706 . 86 


26.59 


10 


78.540 


8.86 


30^ 


730.62 


27.03 


10^ 


86.590 


9-30 


3.1 


754-77 


27.47 


II 


95.03 


9-75 


31^ 


779-31 


37.92 


Hi 


103.87 


10. 19 


32 


804.25 


28.^6 


12 


113. 10 


10.63 


32i 


829.58 


28.80 


12J 


122.72 


11.08 


33 


855.30 


29.25 


13 


132.73 


11.52 


33i 


881.41 


29.69 


i3i 


143-14 


II .96 


34 


907-92 


30.13 


14 


153-94 


12.41 


Uh 


934-82 


30.57 


i4i 


165-13 


12.85 


35 


962. II 


31.02 


15 


176.72 


13.29 


35^ 


989.80 


31.46 


i5i 


188.69 


13-74 


36 


1017.88 


31.90 


16 


201 .06 


14.18 


36i 


1046.35 


32.35 


16^ 


213-83 


14.62 


37 


1075.21 


32.79 


17 


226.98 


15-07 


37i 


1104.47 


33.23 


17* 


240.53 


15-51 


38 


1134. 12 


33.68 


18 


254-47 


15-95 


38I 


1164. 16 


34-12 


i8i 


268.80 


16.40 


39 


1194-59 


34 56 


19 


283.53 


16.84 


39i 


1225.42 


35.0I 


19^ 


298.65 


17.28 


40 


1256.64 


35-45 


20 


314.16 


17.72 


4oi 


1288.25 


35.89 


20^ 


330.06 


18.17 


41 


1320. 26 


36 . 34 


21 


346.36 


18.61 


41* 


1352.66 


36.78 



240 



THE ART OF PATTERN-MAKING, 



AREAS OF CIRCLES, AND LENGTHS OF THE SIDES OF 
SQUARES OF THE SAME A.V.nA.~Continued. 



Diam. of 


Area of Circle 


Sides rf Sq. 


Diam. of 


Area of Circle 


S'des of Sq. 


Circle in 


in Square 


of Same 


Circle in 


in Square 


of Same 


Inches. 


Inches. 


Area in 


Inches. 


Inches. 


Area in 






Sq. Ins. 






Sq. Ins. 


42 


1385.45 


37-22 


51^ 


2083.08 


45.64 


42^ 


1418.63 


37-66 


52 


2123.72 


46.08 


43 


1452.20 


38.11 


52i 


2164.76 


46.53 


43i 


1486.17 


38.55 


53 


2206. 19 


46.97 


44 


1520.53 


38.99 


53i 


2248.01 


47-41 


44^ 


1555-29 


39.44 


54 


2290. 23 


47-86 


45 


1590.43 


39.88 


5Ah 


2332-83 


48.30 


45^ 


1625.97 


40.32 


55 


2375-83 


48.74 


46 


1661 .91 


40.77 


55i 


2419.23 


49.19 


46i 


1698.23 


41 .21 


56 


2463.01 


49.63 


47 


1734-95 


41.65 


56i 


2507.19 


50.07 


47i 


1772.06 


42. 10 


57 


2551-76 


50.51 


48 


1809.56 


42.58 


57i 


2596.73 


50.96 


48^ 


1847.46 


42.98 


58 


2642 .09 


51-40 


49 


1885.75 


43.43 


58i 


2687.84 


51.84 


49i 


1924-43 


43.87 


59 


2733-98 


52.29 


50 


1963-50 


44.31 


59i 


2780.51 


52.73 


50J 


2002 .97 


44.75 


60 


2827.74 


53-17 


51 


2042 . 83 


45 -20 


6oi 


2874.76 


53-62 



XLVII. 
PRISMOIDAL FORMULA. 

(One Rule for the Contents of Various Bodies.) 

A PRiSMOiD is a solid bounded by six plane sur- 
faces, only two of which are parallel. 

Every one who has had occasion to figure out 
the volume or contents of any regularly formed 
geometrical body has been perplexed in trying to 
remember the exact rule for each and the way to 
apply it. It is a happy state of the memory when 
every rule can be called to mind exactly when 
wanted. One rule is more easily remembered 
than a dozen. The following rule will solve all 
the problems of solidity for regular bodies : 

• 11 ( The area of the base, 
Add ' 



^1 ^ The area of the top, 
tosfetner i 

' Four times the area of the middle section. 

Multiply this sum by one sixth of the perpen- 
dicular height. The resulting product is the cubical 

contents or volume required. 

241 



242 THE ART OF PATTERN-MAKING, 

Applying the rule to a cone of lo inches diameter 
of base and 12 inches perpendicular height: 

The area of base 78.54 

The area of top 00.00 

Four times area of middle section 78.54 

157.08 
Multiplied by one sixth of height 2 

The volume in cubic inches equals 314.16 

It will be observed of a cone that the middle 
section is a circle one half the diameter of the base, 
which is equal to one fourth its area; or, to state 
in another way, four times the area of a 5 -inch 
circle is equal to the area of a lo-inch circle. 

The rule applied to a cylinder of 10 inches diam- 
eter and 12 inches in height: 

Area of base 78.54 

'' ''top 78.54 

Four middle areas 314.16 

The sum of these equals .471.24 

Multiplied by one sixth of height 2 

The volume in cubic inches equals 942.48 

This result agrees with the mathematical demon- 
stration that a cylinder has three times the volume 
of a cone of the same height and diameter of base. 

The rule applied to a cube of 12 inches: 



PRISMOIDAL FORMULA, 243 

The area of base 1 44 

" " "top 144 

Four middle areas 576 



The sum equals 864 

MultipHed by one sixth the height 2 



Volume in cubic inches equals 1728 

The rule applies equally to pyramids and prisms 
of whatever form of base or end. It also applies 
to frustums of pyramids, cones, and prisms. 

Whether any of these bodies have their axes 
perpendicular to the base or not, this rule applies 
all the same, care being taken to use the perpendic- 
ular height, never the slant height. 

To find the contents of a sphere 12 inches in 
diameter, use the rule the same way as for the 
cone, thus : 

The area of base 00 . 00 

" " "top oc.oo 

Four middle areas 452 . 39 



The sum of these equals 452 • 39 

Multiplied by one sixth of the height . . 2 

Volume in cubic inches equals 904. 78 

There are some bodies formed like cigars, or 
that have what is called spindle shape, which 
require a little preparation before applying the 
rule for obtaining their contents. For such they 



244 THE ART OF PATTERN-MAKING. 

must first be considered to be divided transversely 
at their largest part, and then calculate each part 
separately and add the results together for the sum. 
In forms like these which have swelled sides 
there must be some means of counting in the 
swell, or convexity of these solids, and this very 
feature is included in the measures of this rule. 
The elements called ' ' four times the area of middle 
section" brings in the swell and includes the differ- 
ence between the volume of a cone of straight 
sides and having the same base and height, and 
of the spindle shape having convex sides. This 
element of the rule also covers the cases of cone-like 
figures having concave or hollow sides. Atten- 
tion is particularly called to the necessity of taking 
in the exact measures of these and other similar 
forms, which every rule requires if the correct 
volume be sought for, because this result in every 
case can only be obtained from all the essential di- 
mensions. 



XLVIII. 

TO COMPUTE THE AREA OF A FIGURE 
BOUNDED BY A CURVE. 

The following rule, known as Simpson's, is 
the one commonly used to compute the area of 
irregular figures: 

Rule : Divide the line ab into any number of equal 
parts by perpendiculars from base, as i, 2, 3, etc., 
which will give an odd number of points of division. 
Measure length of these perpendiculars and proceed 
as follows: To the lengths of the first and last 
ordinates add four times the lengths of all the even- 
numbered ordinates, and twice the sum of the odd ; 
multiply their sum by one third of the distance be- 
tween the ordinates, and the product will give the 
required area. 

Required the area of a space 40 ft. long bounded 
on one side by a curve the ordinates of which are 
given in Fig. 215. 

245 



246 



THE ART OF PATTERN-MAKING. 



_5.45 



3.75 




_3.25 



5.45 



Fig, 215, 



AREA OF A FIGURE BOUNDED BY A CURIAE. 



247 









EXAMPLE. 






Even. 


Odd. 


Sum. 




No. 
Ord. 


Length Ord. 


No. 
Ord. 


Length Ord. 




I 

2 

4 
6 

8 


4- 
5-5 

4- 
3- 
5. 

21.5X4 = 86 


3 

5 
7 
9 


4-5 
3.5 
4- 
6. 


a. 2. 

^•3-5 
86. 

36. 
127.5X1 = 170 






18.0X2=36 


sq. ft. 



The following is another rule which gives fairly 
accurate results, the accuracy depending in a great 
measure on the number of divisions and their 
mean lengths: 

Divide the line ab into any number of equal 
parallel strips by perpendiculars from the base, 
as in the previous case; measure the mean lengths 
of the strips, as indicated by the dotted lines; 
multiply the sum of the mean lengths by the width 
of a strip, and the product will give the area. 



example;. 



No. Ord. 


Lengths Ord. 


I 


3. 


2 


5 




3 


5 


45 


4 


4 




5 


3 


75 


6 


3 




7 


3 


25 


8 


4 


4 


9 


5 


45 


10 


5 


2 




42 


50X4 = 170 sq. ft. 



XLIX. 

WEIGHTS AND MEASURES. 

AVOIRDUPOIS OR ORDINARY COMMERCIAL WEIGHT. 

UNITED STATES AND BRITISH. 



Ton. 


Cwts. 


Pounds. 


Ounces. 


I . 
0.050 


20. 
I . 
0.0089 


2240. 
112. 
I . 
0.0625 


35840. 

1792. 

16. 

I . 



I pound = 27.7 cubic inches of distilled water at its maximum 
density (39° Fahrenheit). 



LONG MEASURE. 

UNITED STATES AND BRITISH. 



Miles. 


Rods. 


Yards. 


Feet. 


Inches. 


I . 

0.003125 

0.000568 

0.0001894 

0.0000158 


320. 
I . 

O.1818 
. 0606 
0.005051 


1760. 

5-5 
I . 

0.3333 
0.02778 


5280. 
16.5 
3. 
I . 
0.08333 


63360. 
198. 

36. 

12. 

I . 



The British measures are shorter than those of the U. S. by about 
I part in 17230, or 3.677 inches in a mile. 

A fathom = 6 feet. A Gunter's surveying chain = 66 feet or 4 rodis, 
80 chains making a mile. 

248 



IVEIGHTS AND MEASURES. 



249 



SQUARE OR LAND MEASURE. 

UNITED STATES AND BRITISH. 



Sq. 
Miles. 


Acres. 


Sq. Rods. 


Sq. Yards. 


Sq. Feet. 


Sq. Inches. 


I . 


640. 
I . 


102400. 
160. 
I . 
0.0331 


3097600. 
4840. 
30.25 
I . 
0. II I 


27878400. 
43560. 
272.25 
9.0 
I . 
. 00694 


6272640. 

39204. 

1296. 

144. 

I . 



CUBIC OR SOLID MEASURE. 

UNITED STATES AND BRITISH. 

1728 cubic inches=i cubic foot. 

27 cubic feet = I cubic yard. 
A cord of wood == 4^X4^X8' = 128 cubic feet. 

A perch of masonry = 16. 5'X 1.5'X i' = 24.75 cubic feet, but is 
generally assumed at 25 cubic feet. 



DRY MEASURE. 

UNITED STATES ONLY. 



Struck Bush. 


Pecks. 


Quarts. 


Pints. 


Gallons. 


Cubic Inch. 


I 


4 


32. 


64 


8. 


2150. 




I 


8. 


16 


2 . 


537-6 






I . 


2 


0.25 


67 .2 






0.5 


I 


0.125 


33.6 






4- 


8 


I . 


268.8 



A gallon of liquid measure = 231 cubic inches. 

A heaped bushel = i \ struck bushels. The cone in a heaped bushel 
must be not less than 6 inches high. 

A barrel of U. S. hydraulic cement = 300 to 310 lbs., usually, and 
of genuine Portland cement =425 lbs. 

To reduce U. S. dry measures to British imperial of the same 
name, divide by 1.032. 



250 THE ART OF PATTERN-MAKING. 

NAUTICAL MEASURE. 

A nautical or sea mile is the length of a minute of longitude of 
the earth at the equator at the level of the sea. It is assumed 
= 6086.07 feet = 1. 152664 statute or land miles by the United States 
Coast Survey. 

3 nautical miles = i league. 

USEFUL FORMULA IN MENSURATION. 

1. Diam. X .8862= Side of an equal square. 

2. Circum.X .2821= " " " " 

3. Diam. X . 7071 =Side of an inscribed square. 

4. Circum.X .2251= " " " 

5. Area X .6366= " " " 

6. Diam. Xi. 3468= Side of an equilateral triangle. 

7. Circum.X .3 183 = Diameter of circle. 

8. Diam. X 3. 14 16= Circumference of circle. 

9. Side of square X 1.4 142 =Diam. of circumscribing circle. 

10. Side of square X4.443 =Circum. of " " 

1 1. Side of square X i . 1 28 = Diam. of circle equal in area. 

12. Side of square X3.545 =Circum. " " " " " 

13. Square of diam. X .7854 = Area of circle. 

14. Square of circum. X .07958= " " " 

15. Square of radius X3.1416 = " " " 

16. Half of circum, Xhalf diameter= Area of circle. 

17. Diam. X 0.7 854 =Side of square of equal periphery as circle. 

18. Side of square X i -2732 =Diam. of circle of equal periphery 

as square. 

19. Base X perpendicular height = Area of parallelogram. 

20. Base Xhalf perpendicular height = Area of triangle. 

2 1 . Half the sum of parallel sides X perpendicular height = Area 

of trapezoid. 

22. Area of trapezium is found by dividing the figure into two 

triangles. 

23. Long diam. X short diam. X 0.7854= Area of ellipse. 

24. Sum of sides Xhalf perpendicular distance from center to sides 

= Area of any regular polygon. 

25. Circum. X height plus area of the two ends= Surface of cylinder. 

26. Diam. X 3.1416 = Surface of sphere. 
Circum. X diameter " " " " 



IVEIGHTS AND MEASURES. 251 

27. Circum. or periphery X half slant height convex surface of cone 
or pyramid; for the entire surface add area of base to 
above product. 

SOLID CONTENTS. 

Prism, right or oblique, = Area of base X perpendicular height. 

Cylinder, right or oblique, = Area of section at right angles to 
sides X length of side. 

Sphere = Diameter cubed X o . 5 2 36 ; also = Surface X i /6 diameter. 

Pyramid or cone, right or obUque, regular or irregular, = Area 
of baseX 1/3 perpendicular height. 



INDEX. 



Area of a figure hounded by a 
curve, to compute, 245. 

Band-saws, breakage, 18. 

speeds, 17. 
Bars of various metals, weight per 

one inch in length of round 

and square, 237. 
Beam-engine, cylinder for, 41. 
Belt-pulleys and fly-wheels, 160. 
Bench vises, 23. 
Board measure, 226. 
Box machine, Daniels' plane and 

core, 20. 

Castings, allowage for shrinkage 
and finishing, 27. 
how to approximate weight of, 

236. 
strength of, increases by press- 
ure, 43. 

Circles, areas of, and length of 
sides of squares of equal area, 
239. 

Circular saws, care and use of, 15. 
speed of, 16. 

Clay, pattern made of, I. 

Cylinder mould, illustrating build- 
ing. 40. 

Cylinder, pattern work for, 39. 

Decimal equivalents and trigono- 
metrican expressions, table of, 
231. 
millimeters and fractions of 
millimeters, table of, 230. 



Deck-lug, pattern of, 83. 

Device for sweeping up screws of 
increasing pitch from hub to 
periphery, 69. 

Distributing work, 35. 

Drawings, duty of foreman to ex- 
amine, 26. 
section-lining mechanical, 190. 

Elbow, pattern work for, 44. 
Elbows, wood lagging for, 171. 

Fillets, wax, 222. 

Fracture, behavior of fluid metals, 
liability to, in the casting cool- 
ing, 28. 

Gear-wheels, teeth of, 155. 
Geometry, 192. 
Globe-valve, pattern for, 129. 
Glue and its use, 168. 
Gun-mount pedestal, pattern for, 
100. 

Hand-planers, good rule for using, 

33- 
speed of, 19. 
Hand-saws, filing, 219. 

Lathes and lathe-work, 175. 

wood-turning, 14. 
Launch-engine, pattern of, 78. 
Loam moulding, patterns for, 36. 
Loose pieces, 170. 

Machines, accidents from, 32. 
253 



254 



INDEX. 



Marine engine, pattern work for a 
high-pressure cylinder of, 93. 

Marking, handy straight-edge for, 
218. 

Moulding, dry-sand loam, 6. 

Mould for kettle, sweeping up a, 

37- 
Mould, pressure of metal on bottom, 
42. 

Nails, mensuration and steel-wire 
finishing, 232, 
steel-wire common, 233. 
Nautical measure and useful for- 
mula in mensuration, 250. 

Oblique chute, pattern for, 137. 

Pattern-maker's bench, 22. 
Pattern-makers, qualifications of, 
II. 

who may become, 12. 
Pattern-making, examples of good 
^ practice in, 34, 
Pattern of i3"-rifle projectile, 74. 
Patterns, best material for, 3. 

different classes of, 25. 

finishing, 7. 

for green-sand moulding, 5. 

hard woods for, 4. 

marking, recording, and storing, 
184. 

standard, 166. 

with branches, 143. 
Pattern-shop, best arrangement of, 

13- 

economy in the use of material 

and running expenses, 30. 
management of a modern, 24. 



Pattern, wax, 2. 

Pedestal, pattern for a, 56. 

Prismoi(lal formula, 241. 

Screw propeller, cast entire, pat- 
tern of, 104. 

Screw propellers, constructing 
small, 123. 
pattern-work for large, cast en- 
tire, 61. 
with separable blades, method 
of making pattern, 112. 

Screws, standard wood, 234. 

Shop, cleaning, 31. 
useful rules, 200. 

Shrinkage and finishing, allow- 
ances for, 8. 

Shrinkage rule, making, 216. 

Shrinkage, table of allowances for, 
of different metals, 29. 

Steam-cylinder, pattern work for 
marine engine, 49. 

Timber, compute volume of square, 
227. 
measure, 228. 

Trimmers and grinders, 21. 

Two-bladed screw, working draw- 
ing, 71. 

Water-collar, pattern for, 88. 
Weights and measures, 248. 

solid contents, 251. 
Wooden face-plates, 182. 
Wood-screws in end grain, insert- 
ing, 224. 
Woods, shrinkage of, 3, 10. 

strength and weight of, 229. 

warping of, 9. 



SHORT-TITLE CATALOGUE 

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OF 

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New York. 
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Green's Principles of American Forestry. (Shortly.) 

Grotenfelt's Principles of Modern Dairy Practice. (WoU.) i2mo, 2 00 

Kemp's Landscape Gardening i2mo, 2 50 

Maynard's Landscape Gardening as Applied to Home Decoration i2mo, i 50 

Sanderson's Insects Injurious to Staple Crops i2mo, i 50 

Insects Injurious to Garden Crops. {In preparation.) 
Insects Injuring Fruits. {In preparation.) 

Stockbridge's Rocks and Soils 8vo, 2 50 

Woll's Handbook for Farmers and Dairymen i6mo, 1 50 

ARCHITECTURE. 

Baldwin's Steam Heating for Buildings i2mo, 2 50 

Berg's Buildings and Structures of American Railroads 4to, 5 00 

Birkmire's Planning and Construction of American Theatres Svo, 3 00 

Architectural Iron and Steel Svo, 3 50 

Compound Riveted Girders as Applied in Buildings Svo, 2 00 

Planning and Construction of High Office Buildings Svo, 3 50 

Skeleton Construction in Buildings Svo, 3 00 

Briggs's Modern American School Buildings Svo, 4 00 

Carpenter's Heating and Ventilating of Buildings Svo, 4 00 

Freitag's Architectural Engineering. 2d Edition, Rewritten Svo, 3 50 

Fireproofing of Steel Buildings Svo, 2 50 

French and Ives's Stereotomy Svo, 2 50 

Gerhard's Guide to Sanitary House-inspection i6mo, i 00 

Theatre Fires and Panics .^ . t2mo, i 50' 

1 



Hatfield's American House Carpenter 8vo, 

Holly's Carpenters' and Joiners' Handbook i8mo, 

Johnson's Statics by Algebraic and Graphic Methods 8vo, 

Kidder's Architect's and Builder's Pocket-book i6mo, morocco, 

Merrill's Stones for Building and Decoration Svo, 

Monckton's Stair-building 4to, 

Patton's Practical Treatise on Foundations Svo, 

Siebert and Biggin's Modern Stone-cutting and Masonry Svo, 

Snow's Principal Species of Wood Svo, 

Sondericker's Graphic Statics with AppUcations to Trusses, Beams, and Arches. 
{Shortly.) 

Wait's Engineering'and Architectural Jurisprudence Svo, 

Sheep, 
Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture Svo, 

Sheep, 

Law of Contracts Svo, 

"Woodbury'sFire Protection of Mills Svo, 

Worcester and Atkinson's Small Hospitals, Establishment and Maintenance, 
Suggestions for Hospital Architecture, with Plans for a Small Hospital. 

i2mo. 
The World's Columbian Exposition of 1893 Large 4to, 



ARMY AND NAVY. 

■Bernadou's Smokeless Powder, Nitro-cellulose, and the Theory of the Cellulose 
Molecule i2mo, 

* Bruff's Text-book Ordnance and Gunnery Svo, 

Chase's Screw Propellers and Marine Propulsion Svo, 

Craig's Azimuth 4to, 

Crehore and Squire's Polarizing Photo-chronograph Svo, 

Cronkhite's Gunnery for Non-commissioned Officers 24mO; morocco, 

* Davis's Elements of Law Svo, 

* Treatise on the Military Law of United States Svo, 

* Sheep 

De Brack's Cavalry Outpost Duties. (Carr.) 24mo, morocco, 

Dietz's Soldier's First Aid Handbook i6mo, morocco, 

* Dredge's Modern French kv^tU^y 4to, half morocco, 

Durand's Resistance and Propulsion of Ships Svo, 

* Dyer's Handbook of Light Artillery i2mo, 

Eissler's Modern High Explosives Svo, 

* Fiebeger's Text-book on Field Fortification Small Svo, 

Hamilton's The Gunner's Catechism iSmo, 

* Hoff's Elementary Naval Tactics Svo, 

Ingalls's Handbook of Problems in Direct Fire Svo, 

* BaUistic Tables Svo, 

* Lyons's Treatise on Electromagnetic Phenomena. Vols. I. and II . . Svo, each, 

* Mahan's Permanent Fortifications. (Mercur.) Svo, half morocco, 

Manual for Courts-martial i6mo morocco, 

* Mercur's Attack of Fortified Places i2mo, 

* Elements of the Art of War Svo, 

Metcalf's^Cost of Manufactures — And the Administration of Workshops, PubUc 

and Private 8vo, 

* Ordnance and Gunnery i2mo, 

Murray's Infantry Drill Regulations iSmo, paper, 

* Phelps's Practical Marine Surveying Svo, 

Powell's Army Officer's Examiner i2mo, 

Sharpe's Art of Subsisting Armies in War iSmo, morocco, 

2 



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* Walke's Lectures on Explosives 8vo, 4 00 

* Wheeler's Siege Operations and Military Mining 8vo, 2 00 

Winthrop's Abridgment of Military Law i2mo, 2 50 

WoodhuU's Notes on Military Hygiene i6mo, i 50 

Young's Simple Elements of Navigation i6mo, morocco, i 00 

Second Edition, Enlarged and Revised i6mo, morocco, 2 00 



ASSAYING. 

Fletcher's Practical Instructions in Quantitative Assaying -with the Blowpipe. 

i2mo, morocco, 

Furman's Manual of Practical Assaying 8vo, 

Miller's Manual of Assaying i2mo, 

O'Driscoll's Notes on the Treatment of Gold Ores Svo, 

Ricketts and Miller's Notes on Assaying Svo, 

Ulke's Modern Electrolytic Copper Refining Svo, 

Wilson's Cyanide Processes i2mo, 

Chlorination Process i2mo. 



ASTRONOMY. 

Comstock's Field Astronomy for Engineers Svo, 

Craig's Azimuth 4to, 

DooUttle's Treatise on Practical Astronomy Svo, 

Gore's Elements of Geodesy Svo, 

Ha3rford's Text-book of Geodetic Astronomy Svo, 

Merriman's Elements of Precise Surveying and Geodesy Svo, 

* Michie and Harlow's Practical Astronomy Svo, 

* White's Elements of Theoretical and Descriptive Astronomy i2mo. 



BOTANY. 

Davenport's Statistical Methods, with Special Reference to Biological Variation. 

i6mo, morocco, i 25 

Thome and Bennett's Structural and Physiological Botany i6mo, 2 25 

Westermaier's Compendium of General Botany. (Schneider.) Svo, 2 00 



CHEMISTRY. 

Adriance's Laboratory Calculations and Specific Gravity Tables i2mo, i 25 

Allen's Tables for Iron Analysis Svo, 3 00 

Arnold's Compendium of Chemistry. (Mandel.) (In preparation.) 

Austen's Notes for Chemical Students i2mo, i 50 

Bernadou's Smokeless Powder. — Nitro-cellulose, and Theory of the Cellulose 

Molecule i2mo, 

Bolton's Quantitative Analysis Svo, 

* Browning's Introduction to the Rarer Elements Svo, 

Brush and Penfield's Manual of Determinative Mineralogy Svo, 

Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood.) . . . .Svo, 

Cohn's Indicators and Test-papers i2mo. 

Tests and Reagents Svo, 

Copeland's Manual of Bacteriology. (In preparation.) 

Craft's Short Course in Qualitative Chemical Analysis. (Schaeffer.). . . . i2mo, 

Drechsel's Chemical Reactions. (Merrill.) i2mo, 

Duhem's Thermodynamics and Chemistry. (Burgess.) (Shortly.) 

Eissler's Modern High Explosives Svo, 4 00 

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25 



Effront's Enzymes and their Applications. (Prescott.) 8vo, 3 00 

Erdmanii's Introduction to Chemical Preparations. (Dunlap,) i2mo, i 25 

Fletcher's Practical Instructions in Quantitative Assaying with the Blowpipe. 

i2mo, morocco, i 50 

Fowler's Sewage Works Analyses i2mo, 2 00 

Fresenius's Manual of Qualitative Chemical Analysis. (Wells.) 8vo, 5 00 

Manual of Qualitative Chemical Analysis. Parti. Descriptive. (Wells.) 

8vo, 3 00 
System of Instruction in Quantitative Chemical Analysis. (Cohn.) 
2 vols. (Shortly.) 

Fuertes's Water and PubUc Health i2mo, 

Furman's Manual of Practical Assaying Svo, 

Gill's Gas and Fuel Analysis for Engineers i2mo, 

Grotenfelt's Principles of Modern Dairy Practice. (WoU.) i2mo, 

Hammarsten's Text-book of Physiological Chemistry. (Mandel.) Svo, 

Helm's Principles of Mathematical Chemistry. (Morgan.) i2mo. 

Hinds's Inorganic Chemistry '. Svo, 

♦ Laboratory Manual for Students i2mo, 

Holleman's Text-book of Inorganic Chemistry. (Cooper.) Svo, 

Text-book of Organic Chemistry. (Walker and Mott.) Svo, 

Hopkins's Oil-chemists' Handbook Svo, 

Jackson's Directions for Laboratory Work in Physiological Chemistry. .Svo, 

Keep's Cast Iron Svo, 

Ladd's Manual of Quantitative Chemical Analysis i2mo, 

Landauer's Spectrum Analysis. (Tingle.) Svo, 

Lassar-Cohn's Practical Urinary Analysis. (Lorenz.) i2mo. 

Leach's The Inspection and Analysis of Food with Special Reference to State 

Control. (In preparation.) 
Lob's Electrolysis and Electrosynthesis of Organic Compounds. (Lorenz.) i2mo, 

Mandel's Handbook for Bio-chemical Laboratory i2mo, 

Mason's Water-supply. (Considered Principally from a Sanitary Standpoint.) 

3d Edition, Rewritten Svo, 

Examination of Water. (Chemical and Bacteriological.) i2mo, 

Meyer's Determination of Radicles in Carbon Compounds. (Tingle.). . i2mo. 

Miller's Manual of Assaying i2mo, 

Mlxter's Elementary Text-book of Chemistry i2mo, 

Morgan's Outline of Theory of Solution and its Results i2mo. 

Elements of Physical Chemistry i2mo, 

Nichols's Water-supply. (Considered mainly from a Chemical and Sanitary 

Standpoint, 1SS3.) Svo, 

O'Brine's Laboratory Guide in Chemical Analysis Svo, 

O'DriscoU's Notes on the Treatment of Gold Ores Svo, 

Ost and Kolbeck's Text-book of Chemical Technology. (Lorenz — Bozart.) 
(In preparation.) 

* Penfield's Notes on Determinative Mineralogy and Record of Mineral Tests. 

Svo, paper, 50 
Pictet's The Alkaloids and their Chemical Constitution. (Biddle.) (In 
preparation.) 

Pinner's Introduction to Organic Chemistry. (Austen.) i2mo, i 50 

Poole's Calorific Power of Fuels Svo, 3 00 

* Reisig's Guide to Piece-dyeing Svo, 25 00 

Richards and Woodman's Air , Water, and Food from a Sanitary.Standpoint . Svo, 2 00 
Richards's Cost of Living as Modified by Sanitary Science i2mo, i 00 

Cost of Food, a Study in Dietaries i2mo, i 00 

* Richards and Williams's The Dietary Computer Svo, i 50 

Ricketts and Russell's Skeleton Notes upon Inorganic Chemistry. (Part I. — 

Non-metallic Elements.) Svo, morocco, 75 

Ricketts and Miller's Notes on Assaying Svo, 3 00 

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Rideal's Sewage and the Bacterial Purification of Sewage 8vo, 

Ruddiman's Incompatibilities in Prescriptions 8vo, 

Schimpf s Text-book of Volumetric Analysis i2mo, 

Spencer's Handbook for Chemists of Beet-sugar Houses i6mo, morocco, 

Handbook for Sugar Manufacturers and their Chemists. . i6mo, morocco, 
Stockbridge's Rocks and Soils 8vo, 

* Tillman's Elementary Lessons in Heat 8vo, 

* Descriptive General Chemistry 8vo 

Treadwell's Qualitative Analysis. (Hall.) 8vo, 

Turneaure and Russell's Public Water-supplies 8vo, 

Van Deventer's Physical Chemistry for Beginners. (Boltwood.) i2mo, 

* Walke's Lectures on Explosives 8vo, 

Wells's Laboratory Guide in Qualitative Chemical Analysis 8vo, 

Short Course in Inorganic Qualitative Chemical Analysis for Engineering 

Students i2mo, 

Whipple's Microscopy of Drinking-water 8vo, 

Wiechmann's Sugar Analysis Small 8vo, 

Wilson's Cyanide Processes i2mo, 

Chlorination Process i2mo 

Wulling's Elementary Course in Inorganic Pharmaceutical and Medical Chem- 
istry i2mo, 2 00 

CIVIL ENGINEERING. 

BRIDGES AND ROOFS. HYDRAULICS. MATERIALS OF ENGINEERING. 

RAILWAY ENGINEERING. 

Baker's Engineers' Surveying Instruments i2mo, 

Bixby's Graphical Computing Table Paper, 19^X24^ inches. 

** Burr's Ancient and Modern Engineering and the Isthmian Canal. (Postage, 

27 cents additional.) Svo, net, 3 

Comstock's Field Astronomy for Engineers 8vo, 

Davis's Elevation and Stadia Tables Svo, 

Elliott's Engineering for Land Drainage i2mo. 

Practical Farm Drainage i2mo, 

Folwell's Sewerage. (Designing and Maintenance.) Svo, 

Freitag's Architectural Engineering. 2d Edition, Rewritten Svo, 

French and Ives's Stereotomy Svo, 

Goodhue's Municipal Improvements i2mo, 

Goodrich's Economic Disposal of Towns' Refuse Svo, 

Gore's Elements of Geodesy 8vo , 

Hasrford's Text-book of Geodetic Astronomy Svo, 

Howe's Retaining Walls for Earth i2mo, 

Johnson's Theory and Practice of Surveying Small Svo, 

Statics by Algebraic and Graphic Methods Svo, 

Kiersted's Sewage Disposal i2mo, 

Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2mo, 
Mahan's Treatise on Civil Engineering. (1873.) (Wood.) Svo 

* Descriptive Geometry . . . . ; Svo, 

Merriman's Elements of Precise Surveying; and Geodesy Svo, 

Elements of Sanitary Engineering Svo, 

Merriman and Brooks's Handbook for Surveyors i6mo, morocco, 

Nugent's Plane Surveying Svo, 

Ogden's Sewer Design i2mo, 

Patton's Treatise on Civil Engineering Svo, half leather. 

Reed's Topographical Drawing and Sketching 4to, 

Rideal's]Sewage and the Bacterial Purification of Sewage Svo, 

Siebert and Biggin's Modern Stone-cutting and Masonry Svo, 

Smith's Manual of Topographical Drawing. (McMillan.) Svo, 

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Sondericker's Graphic Statics, with 2-pplications to Trusses, Beams, and 
Arches. (Shortly.) 

* Trantwine's Civil Engineer's Pocket-book i6mo, morocco, 

Wait's Engineering and Architectural Jurisprudence 8vo, 

Sheep, 
Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture 8vo, 

Sheep, 

Law of Contracts 8vo, 

Warren's Stereotomy — Problems in Stone-cutting Svo, 

Webb's Problems in the U?e and Adjustment of Engineering Instruments. 

i6mo, morocco, 

* Wheeler's Elementary Course of Civil Engineering Svo, 

Wilson's Topographic Surveying Svo, 



BRIDGES AND ROOFS. 

Boiler's Practical Treatise on the Construction of Iron Highway Bridges. .Svo, 2 00 

* Thames River Bridge 4to, paper, 5 00 

Burr's Course on the Stresses in Bridges and Roof Trusses, Arched Ribs, and 

Suspension Bridges Svo, 3 50 

Du Bois's Mechanics of Engineering. Vol. II Small 4to, 10 00 

Foster's Treatise on Wooden Trestle Bridges 4to, 5 00 

Fowler's Coffer-dam Process for Piers Svo, 2 50 

Greene's Roof Trusses Svo, i 2s 

Bridge Trusses Svo, 2 50 

Arches in Wood, Iron, and Stone Svo, 2 50 

Howe's Treatise on Arches Svo 4 00 

Design of Simple Roof-trusses in Wood and Steel Svo, 2 00 

Johnson, Bryan, and Turneaure's Theory and Practice in the Designing of 

Modern Framed Structures Small 4to, 10 00 

Merriman and Jacoby's Text-book on Roofs and Bridges: 

Part I. — Stresses in Simple Trusses Svo, 2 50 

Part II. — Graphic Statics Svo, 2 50 

Part III. — Bridge Design. 4th Edition, Rewritten Svo, 2 50 

Part IV. — Higher Structures Svo, 2 50 

Morison's Memphis Bridge 4to, 10 00 

Waddell's De Pontibus, a Pocket-book for Bridge Engineers. . . i6mo, morocco, 3 00 

Specifications for Steel Bridges i2mo, i 25 

Wood's Treatise on the Theory of the Construction of Bridges and Roofs. Svo, 2 00 
Wright's Designing of Draw-spans: 

Part I. — Plate-girder Draws Svo, 2 50 

Part II. — Riveted-truss and Pin-connected Long-span Draws Svo, 2 50 

Two parts in one volume Svo, 3 50 



HYDRAULICS. 

Bazin's Experiments upon the Contraction of the Liquid Vein Issuing from an 

Orifice. (Trautwine.) Svo, 

Bovey's Treatise on Hydraulics Svo, 

Church's Mechanics of Engineering Svo, 

Diagrams of Mean Vefocity of Water in Open Channels paper, 

CoflSn's Graphical Solution of Hydraulic Problems i6mo, morocco, 

Flather's Dynamometers, and the Measurement of Power i2mo, 

Folwell's Water-supply Engineering Svo, 

Frizell's Water-power Svo, 

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Fuertes's Water and Public Health i2mo, i 50 

Water-filtration Works i2mo, 2 50 

Ganguillet and Kutter's General Formula for the Uniform Flow of Water in 

Rivers and Other Channels. (Bering and Trautwine.) 8vo, 4 00 

Hazen's Filtration of Public Water-supply 8vo, 3 00- 

Hazlehurst's Towers and Tanks for Water- works 8vo , 2 5a 

Herschel's 115 Experiments on the Carrying Capacity of Large, Riveted, Metal 

Conduits 8vo, 2 00 

Mason's Water-supply. (Considered Principally from a Sanitary Stand- 
point.) 3d Edition, Rewritten 8vo, 4 00 

Merriman's Treatise on Hydraulics, gth Edition, Rewritten 8vo, 5 00 

* Michie's Elements of Analytical Mechanics 8vo, 4 00 

Schuyler's Reservoirs for Irrigation, Water-power, and Domestic Water- 
supply Large 8vo, 5 00 

** Thomas and Watt's Improvement of Riyers. (Post., 44 c additional), 4to, 6 ook 

Turneaure and Russell's Public Water-supplies 8vo. 5 oa 

Wegmann's Desicn and Construction of Dams 4to, 5 00 

Water-supolv of the City of New York from 1658 to 1895 4to, 10 oo» 

Weisbach's Hydraulics and Hydraulic Motors. (Du Bois.) 8vo, 5 00 

Wilson's Manual of Irrigation Engineering Small 8vo, 4 00 

Wolff's Windmill as a Prime Mover Svo.l's oo 

Wood's Turbines 8vo, 2 50 

Elements of Analytical Mechanics 8vo, 3 00 



MATERIALS OF ENGINEERING. 

Baker's Treatise on Masonry Construction 8vo, 

Roads and Pavements 8vo, 

Black's United States Public Works Oblong 4to, 

Bovey's Strength of Materials and Theory of Structures 8vo, 

Burr's Elasticity and Resistance of the Materials of Engineering. 6th ^Edi- 
tion, Rewritten 8vo, 

Byrne's Highway Construction 8vo. 

Inspection of the Materials and Workmanship Employed in Construction. 

i6mo, 

Church's Mechanics of Engineering 8vo, 

Du Bois's Mechanics of Engineering. Vol. I Small 4to, 

Johnson's Materials of Construction Large 8vo, 

Keep's Cast Iron 8vo, 

Lanza's Applied Mechanics 8vo, 

Martens's Handbook on Testing Materials. (Henning.) 2 vols 8vo, 

Merrill's Stones for Building and Decoration 8vo, 

Merriman's Text-book on the Mechanics of Materials 8vo, 

Strength of Materials i2mo, 

Metcalf's Steel. A Manual for Steel-users i2mo, 

Patton's Practical Treatise on Foundations 8vo, 

Rockwell's Roads and Pavements in France i2mo. 

Smith's Wire : Its Use and Manufacture Small 4to, 

Materials of Machines i2mo. 

Snow's Principal Species of Wood 8vo, 

Spalding's Hydraulic Cement i2mo. 

Text-book on Roads and Pavements i2mo, 

Thurston's Materials of Engineering. 3 Parts 8vo, 

Part I. — Non-metallic!Materials of Engineering and Metallurgy 8vo, 

Part II. — Iron and Steel 8vo, 

Part III. — A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents 8vo, 2' 50 

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Thurston's Text-book of the Materials of Construction 8vo, 5 00 

Tillson's Street Pavements and Paving Materials 8vo, 4 00 

Waddell's De Pontibus. (A Pocket-book for Bridge Engineers.) . . i6mo, mor., 3 00 

Specifications for Steel Bridges , i2mo, i 25 

Wood's Treatise on the Resistance of Materials, and an Appendix on the Pres- 
ervation of Timber 8vo, 2 00 

Elements of Analytical Mechanics Svo, 3 00 



RAILWAY ENGINEERING. 

Andrews's Handbook for Street Railway Engineers. 3X5 inches, morocco, i 25 

Berg's Buildings and Structures of American Railroads 4to, 5 00 

Brooks's Handbook of Street Railroad Location i6mo, morocco, 1 50 

Butts's Civil Engineer's Field-book i6mo, morocco, 2 50 

Crandall's Transition Curve i6mo, morocco, i 50 

Railway and Other Earthwork Tables Svo, i 50 

Dawson's "Engineering" and Electric Traction Pocket-book. i6mo, morocco, 4 00 

Dredge's History of the Pennsylvania Railroad: (1879) Paper, 5 00 

* Drinker's Tunneling, Explosive Compounds, and Rock Drills, 4to, half mor., 25 00 

Fisher's Table of Cubic Yards Cardboard, 25 

Godwin's Railroad Engineers' Field-book and Explorers' Guide i6mo, mor., 2 50 

Howard's Transition Curve Field-book i6mo morocco i 50 

Hudson's Tables for Calculating the Cubic Contents of Excavations and Em- 
bankments Svo, I 00 

Molitor and Beard's Manual for Resident Engineers i6mo, i 00 

Nagle's Field Manual for Railroad Engineers i6mo, morocco. 3 00 

Philbrick's Field Manual for Engineers i6mo, morocco, 3 00 

Pratt and Alden's Street-railway Road-bed Svo, 2 00 

Searles's Field Engineering i6mo, morocco, 3 00 

Railroad Spiral i6mo, morocco i 50 

Taylor's Prismoidal Formulae and Earthwork Svo, 1 50 

* Trautwine's Method of Calculating the Cubic Contents of Excavations and 

Embankments by the Aid of Diagrams Svo, 2 00 

he Field Practice of [Laying Out Circular Curves for Railroads. 

i2mo, morocco, 2 50 

* Cross-section Sheet Paper, 25 

Webb's Railroad Construction. 2d Edition, Rewritten i6mn. morocco. 5 00 

Wellington's Economic Theory of the Location of Railways Small Svo, 5 00 



DRAWING. 

Bart's Kinematics of Machinery Svo, 

* Bartlett's Mechanical Drawing Svo, 

Coolidge's Manual of Drawing Svo, paper, 

Durley's Kinematics of Machines Svo, 

Hill's Text-book on Shades and Shadows, and Perspective Svo, 

Jones's Machine Design: 

Part I. — Kinematics of Machinery Svo, 

Part n. — Form, Strength, and Proportions of Parts Svo, 

MacCord's Elements of Descriptive Geometry Svo, 

Kinematics; or. Practical Mechanism Svo, 

Mechanical Drawing .4to, 

Velocity Diagrams ^ Svo, 

* Mahan's Descriptive Geometry and Stone-cutting Svo, 

Industrial Drawing. (Thompson.) Svo, 

Reed's Topographical Drawing and Sketching 4to, 



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Reid's Course in Mechanical Drawing 8vo, 

Text-book of Mechanical Drawing and Elementary Machine Design. .8vo, 

Robinson's Principles of Mechanism 8vo, 

Smith's Manual of Topographical Drawing. (McMillan.) Svo, 

Warren's Elements of Plane and SoUd Free-hand Geometrical Drawing. . i2mo, 

Drafting Instruments and Operations i2mo, 

Manual of Elementary Projection Drawing i2mo, 

Manual of Elementary Eroblems in the Linear Perspective of Form and 

Shadow i2mo. 

Plane Problems in Elementary Geometry i2mo, 

Primary Geometry i2mo, 

Elements of Descriptive Geometry, Shadows, andlPerspective Svo, 

General Problems of Shades and Shadows 8vo, 

Elements of Machine Construction and Drawing 8vo, 

Problems. Theorems, and Examples in Descriptive Geometrv 8vo, 

Weisbach's Kinematics and the Power of Transmission. (Hermann ao'' 

Klein.) 8vo, 

Whelpley's Practical Instruction in the Art of Letter Engraving i2mo, 

Wilson's Topographic Surveying 8vo, 

Free-hand Perspective 8vo, 

Free-hand Lettering. (In preparation.) 
Woolf's Elementary Course in Descriptive Geometry Large 8vo, 3 00 



ELECTRICITY AND PHYSICS. 

Anthony and Brackett's Text-book of Physics. (Magie.) ... .Small 8vo» 

Anthony's Lecture-notes on the Theory of Electrical Measurements i2mo, 

Benjamin's'History of Electricity Svo, 

Voltaic Cell Svo, 

Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood.). .Svo, 

Crehore and Squier's Polarizing Photo-chronograph Svo , 

Dawson's "Engineering" and Electric Traction Pocket-book. . lomo, morocco, 

Flather's Dvnamometers, and the Measurement of Power i2mo, 

Gilbert's De Magnete. (Mottelay.) Svo, 

Holman's Precision of Measurements Svo, 

Telescopic Mirror-scale Method, Adjustments, and Tests Large Svo 

Lanaauer's Spectrum Analysis. (Tingle.) Svo, 

Le ChateUer's High-temperature Measurements. (Boudouard — liurgess.)i2mo, 
Lob's Electrolysis and Electrosynthesis of Organic Compounds. (Lorenz.) i2mo, 

* Lyons's Treatise on Electromagnetic Phenomena. Vols. I. and li. Svo, each, 

* Michie. Elements of Wave Motion Relating to'Sound'and Light Svo, 

Niaudet's Elementary Treatise on Electric Batteries. (FishoacK. ) i2mo, 

* Parshall and Hobart's Electric Generators Small24to. halflmorocco, 10 00 

* Rosenberg's Electrical Engineering. (Haldane Gee — Kinzbrunner.). . . .Svo, i 50 
Ryan, Norris, and Hoxie's Electrical Machinery. (In preparatiov .'» 

Thurston's Stationary Steam-engines Svo, 2 50 

* Tillman's Elementary Lessons in Heat Svo, i 50 

Tory and Pitcher's Manual of Laboratory Physics Small Svo, 2 00 

Ulke's Modern Electrolytic Copper Refining Svo, 3 00 



LAW. 

* Davis's Elements of Law Svo, 2 50 

* Treatise on the Military Law of United States Svo, 7 00 

* Sheep, 7 50 
ManuarforlCourts-martial i6mo, morocco, i 50 

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Wait's Engineering and Architectural Jurisprudence 8vo, 

Sheep, 
Law of Operations Preliminary to Construction in Engineering'and Archi- 
tecture 8vo, 

Sheep, 

Law of Contracts 8vo, 

Winthrop's Abridgment of Military Law i2mo, 



MANUFACTURES. 

Bernadou's Smokeless Powder — Nitro-cellulose and Theory of the Cellulose 

Molecule i2mo, 2 50 

BoUand's Iron Founder i2mo, 2 50 

" The Iron Founder," Supplement i2mo, 2 50 

Encyclopedia of Founding and Dictionary of Foundry Terms Used_in the 

Practice of Moulding i2mo, 3 00 

Eissler's Modern High Explosives Svo, 4 00 

Effront's Enzymes and their Applications. (Prescott.) Svo, 3 00 

Fitzgerald's Boston Machinist iBmo, i 00 

Ford's Boiler Making for Boiler Makers iSmo, i 00 

Hopkins's Oil-chemists' Handbook Svo, 3 00 

Keep's Cast Iron Svo, 2 50 

Leach's The Inspection and Analysis of Foodlwith SpeciarReference to State 

Control. {In preparation.) 

Metcalf's Steel. A Manual for Steel-users i2mo, 2 00 

Metcalfe's Cost of Manufactures — And the Administration of Workshops, 

Public and Private Svo, S 00 

Meyer's Modern Locomotive Construction 4to, 10 00 

* Reisig's Guide to Piece-dyeing Svo, 25 00 

Smith's Press-working of Metals Svo, 3 00 

Wire : Its Use and Manufacture Small 4to, 3 00 

Spalding's HydrauUc Cement i2mo, 2 00 

Spencer's Handbook for Chemists of Beet-sugar Houses i6mo, morocco, 3 00 

^ andboo\ tor sugar Manutacturers and their Chemists. . . i6mo, morocco, 2 00 
Thurston's Manual of Steam-boilers, their Designs, Construction and Opera- 
tion Svo, 5 00 

♦ Walke's Lectures on Explosives Svo, 4 00 

West's American Foundry Practice i2mo, 2 50 

Moulder's Text-book i2mo, 2 50 

Wiechmann's Sugar Analysis Small Svo, 2 50 

Wolff's Windmill as a Prime Mover Svo,T~3 00 

Woodbury's Fire Protection of Mills Svo,^2 50 



MATHEMATICS. 

Baker's Elliptic Functions Svo, i 50 

* Bass's Elements of Differential Calculus i2mo, 4 00 

Briggs's Elements of Plane Analytic Geometry i2mo, i 00 

Chapman's Elementary Course in Theory of Equations i2mo, i 50 

Compton's Manual of Logarithmic Computations i2mo, i 50 

Davis's Introduction to the Logic of Algebra Svo, i 50 

* Dickson's College Algebra Large i2mo, i 50 

* Introduction to the Theory of Algebraic Equations Large^izmo, i 25 

Halsted's Elements of Geometry Svo, i 75 

Elementary Synthetic Geometry Svo, i 50 

10 



♦Johnson's Three-place Logarithmic Tables: Vest-pocket size paper, is 

103 copies for 5 00 

* Mounted on heavy cardboard, 8 X 10 inches, 25 

10 copies for 2 OO' 

Elementary Treatise on the Integral Calculus Small 8vo, i 5a 

Curve Tracing in Cartesian Co-ordinates i2mo, i 00 

Treatise on Ordinary and Partial Differential Equations Small Svo, 3 50 

Theory of Errors ^nd the Method of Least Squares i2mo, i 50 

* Theoretical Mechanics i2mo, 3 00 

Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2mo, 2 00 

* Ludlow and Bass. Elements of Trigonometry and Logarithmic and Other 

Tables 8vo, 3 00 

Trigonometry and Tables published separately Each, 2 00 

Maurer's Technical Mechanics. {In preparation.) 

Merriman and Woodward's Higher Mathematics Svo, 5 00 

Merriman's Method of Least Squares Svo, 2 oa 

Rice and Johnson's Elementary Treatise on the Differential Calculus. Sm., Svo, 3 oa 

Differential and Integral Calculus. 2 vols, in one Gmall Svo, 2 50 

Wood's Elements of Co-ordinate Geometry Svo, 2 oa 

Trigonometry: Analytical, Plane, and Spherical i2mo, i oa 

MECHANICAL ENGINEERING. 
MATERIALS OF ENGINEERING, STEAM-ENGINES AND BOILERS. 

Baldwin's Steam Heating for Buildings i2mo, 

Barr's Kinematics of Machinery Svo, 

* Bartlett's Mechanical Drawing Svo, 

Benjamin's Wrinkles and Recipes i2mo, 

Carpenter's Experimental Engineering .Svo, 

Heating and Ventilating Buildings Svo, 

Clerk's Gas and Oil Engine Small Svo, 

Coolidge's Manual of Drawing Svo, paper, 

Cromwell's Treatise on Toothed Gearing i2mo, 

Treatise on Belts and Pulleys i2mo, 

Durley's Kinematics of Machines Svo, 

Flather's Dynamometers and the Measurement of Power i2mo, 

Rope Driving i2mo, 

Gill's Gas and Fuel Analysis for Engineers i2mo, 

Hall's Car Lubrication i2mo, 

Hutton's The Gas Engine, (/n preparation.) 
Jones's Machine Design: 

Part I. — Kinematics of Machinery Svo, 

Part II. — Form, Strength, and Proportions of Parts Svo, 

Kent's Mechanical Engineer's Pocket-book i6mo, morocco, 

Kerr's Power and Power Transmission Svo, 

MacCord's Kinematics; or, Practical Mechanism Svo, 

Mechanical Drawing 4to, 

Velocity Diagrams Svo, 

Mahan's Industrial Drawing. (Thompson.) Svo, 

Poole's Calorific Power of Fuels Svo, 

Reid's Course in Mechanical Drawing Svo. 

Text-book of Mechanical Drawing and Elementary Machine Design. .Svo, 

RIchards's Compressed Air i2mo, 

Robinson's Principles of Mechanism Svo, 

Smith's Press- working of Metals Svo, 

Thurston's Treatise on Friction and Lost Work in Machinery and MiU 
Work Svo, 

Animal as a Machine and Prime Motor, and the Laws of Energetics . i2mo, 

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Warren's Elements of Machine Construction and Drawing 8vo, 7 50 

Weisbach's Kinematics and the Power of Transmission, Herrmann — 

Klein.) 8vo, 5 00 

Machinery of Transmission and Governors. (Herrmann — Klein.). .8vo, 5 00 

Hydraulics and Hydraulic Motors, (Du Bois.) Svo, 5 00 

Wolff's Windmill as a Prime Mover Svo, 3 00 

Wood's Turbines. Svo, 2 50 

MATERIALS OF ENGINEERING. 

Bovey's Strength of Materials and Theory of Structures Svo, 7 50 

Burr's Elasticity and Resistance of the Materials of Engineering. 6th Edition, 

Reset Svo, 7 50 

Church's Mechanics of Engineering ." Svo, 6 00 

Johnson's Materials of Construction Large Svo, 6 00 

Keep's Cast Iron Svo , 2 50 

Lanza's Applied Mechanics Svo, 7 50 

Martens's Handbook on Testing Materials. (Henning.) Svo, 7 50 

Merriman's Text-book on the Mechanics of Materials Svo, 4 00 

Strength of Materials i2mo, i 00 

Metcalf's Steel. A Manual for Steel-users i2mo 2 00 

Smith's Wire: Its Use and Manufacture Small 4to, 3 00 

Materials of Machines i2mo, i 00 

Thurston's Materials of Engineering 3 vols , Svo, 8 00 

Part II. — Iron and Steel Svo, 3 50 

Part III. — A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents Svo, 2 50 

Text-book of the Materials of Construction Svo 5 00 

Wood's Treatise on the Resistance of Materials and an Appendix on the 

Preservation of Timber Svo, 2 00 

Elements of Analytical Mechanics Svo, 3 00 



STEAM-ENGINES AND BOILERS. 

Carnot's Reflections on the Motive Power of Heat. (Thurston.) i2mo, i 50 

Dawson's "Engineering" and Electric Traction Pocket-book. .T6mo, mor., 4 00 

Ford's Boiler Making for Boiler Makers iSmo, i 00 

■Goss's Locomotive Sparks Svo, 2 00 

Hemenway's Indicator Practice and Steam-engine Economy i2mo, 2 00 

Hutton's Mechanical Engineering of Power Plants Svo, 5 00 

Heat and Heat-engines '. Svo, 5 00 

Kent's Steam-boiler Economy * Svo, 4 00 

Kneass's Practice and Theory of the Injector Svo, i 50 

MacCord's Slide-valves Svo, 2 00 

Meyer's Modern Locomotive Construction 4to, 10 00 

Peabody's Manual of the Steam-engine Indicator i2mo, i 50 

Tables of the Properties of Saturated Steam and Other Vapors Svo, i 00 

Thermodynamics of the Steam-engine and Other Heat-engines Svo, 5 00 

Valve-gears for Steam-engines Svo, 2 50 

Peabody and Miller's Steam-boilers Svo, 4 00 

Pray's Twenty Years with the Indicator Large Svo, 2 50 

Pupln's Thermodynamics of Reversible Cycles in Gases and Saturated Vapors. 

(Osterberg.) i2mo, i 25 

Reagan's Locomotives : Simple, Compound, and Electric i2mo, 2 50 

Rontgen's Principles of Thermodynamics. (Du Bois.) Svo, 5 00 

Sinclair's Locomotive Engine Running and Management i2mo, 2 00 

Smart's Handbook of Engineering Laboratory Practice i2mo, 2 50 

Snow's Steam-boiler Practice Svo, 3 00 

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Spangler's Valve-gears 8vo, 

Notes on Thermodynamics i2mo, 

Spangler, Greene, and Marshall's Elements of Steam-engineering 8vo, 

Thurston's Handy Tables 8vo, 

Manual of the Steam-engine 2 vols. Svo, 

Part I. — History, Structuce, and Theory Svo, 

Part n. — Design, Construction, and Operation Svo, 

Handbook of Engine and Boiler Trials, and the Use of the Indicator and 

the Prony Brake .• Svo, 

Stationary Steam-engines Svo, 

Steam-boiler Explosions in Theory and in Practice i2mo. 

Manual of Steam-boilers, Their Designs, Construction, and Operation . Svo, 

Weisbach's Heat, Steam, and Steam-engines. (Du Bois.) Svo, 

Whitham's Steam-engine Design Svo, 

Wilson's Treatise on Steam-boilers. (Flather.) i6mo. 

Wood's Thermodynamics, Heat Motors, and Refrigerating Machines. . . .Svo, 



MECHANICS and; MACHINERY."' ^< ...^3 

Barr's Kinematics of Machinery Svo, 

Bovey's Strength of Materials and Theory of Structures Svo, 

Chase's The Art of Pattern-making i2mo, 

Chordal. — Extracts from Letters i2mo. 

Church's Mechanics of Engineering Svo , 

Notes and Examples in Mechanics Svo, 

Compton's First Lessons in Metal-working i2mo, 

Compton and De Groodt's The Speed Lathe i2mo, 

Cromwell's Treatise on Toothed Gearing i2mo, 

Treatise on Belts and Pulleys i2mo, 

Dana's Text-book of Elementary Mechanics for the Use of Colleges and 

Schools i2mo. 

Dingey's Machinery Pattern Making i2mo, 

Dredge's Record of the Transportation Exhibits Building of the World's 

Columbian Exposition of 1893 4to, half morocco, 5 00 

Du Bois's Elementary Principles of Mechanics : 

Vol. I. — Kinematics Svo, 

Vol. n.— Statics Svo, 

Vol. III.— Kinetics Svo, 

Mechanics of Engineering. Vol. I Small 4to, 

Vol. II Small 4to, 

Durley's Kinematics of Machines Svo, 

Fitzgerald's Boston Machinist i6mo, 

Flather 's Dynamometers, and the Measurement of Power i2mo. 

Rope Driving i2mo, 

Goss's Locomotive Sparks Svo, 

Hall's Car Lubrication i2mo. 

Holly's Art of Saw Filing i8mo 

* Johnson's Theoretical Mechanics i2mo, 

Statics by Graphic and Algebraic Methods Svo, 

Jones's Machine Design: 

Part I. — Kinematics of Machinery Svo, 

Part n. — Form, Strength, and Proportions of Parts Svo, 

Kerr's Power and Power Transmission Svo, 

Lanza's Applied Mechanics Svo, 

MacCord's Kinematics; or. Practical Mechanism Svo, 

Velocity Diagrams Svo, 

Maurer's Technical Mechanics, (/n preparation.) 

13 



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Merriman's Text-book on the Mechanics of Materials 8vo, 

* Michie's Elements of Analytical Mechanics 8vo, 

Reagan's Locomotives: Simple, Compound, and Electric i2mo, 

Reid's Course in Mechanical Drawing 8vo, 

Text-book of Mechanical Drawing and Elementary Machine Design. .8vo, 

. Richards's Compressed Air i2mo, 

Robinson's Principles of Mechanism 8vo, 

Ryan, Norris, and Hoxie's Electrical Machinery. {In preparation.) 

Sinclair's Locomotive-engine Running and Management i2mo, 

Smith's Press-working of Metals .8vo, 

Materials of Machines i2mo, 

Spangler, Greene, and Marshall's Elements of Steam-engineering 8vo, 

Thurston's Treatise on Friction and Lost Work in Machinery and Mill 
Work 8vo, 

Animal as a Machine and Prime Motor, and the Laws of Energetics. i2mo, 

Warren's Elements of Machine Construction and Drawing 8vo, 

Weisbach's Kinematics and the Power of Transmission. (Herrmann — 
Klein.). . 8vo, 

Machinery of Transmission and Governors. (Herrmann — Klein. ).8vo. 
Wood's Elements of Analytical Mechanics 8vo, 

Principles of Elementary Mechanics i2mo. 

Turbines 8vo , 

The World's Columbian Exposition of 1893 4to, 

METALLURGY. 

Egleston's Metallurgy of Silver, Gold, and Mercury: 

Vol. I. — Silver 8vo, 7 50 

Vol. n. — Gold and Mercury 8vo, 7 50 

** Iles's Lead-smelting. (Postage 9 cents additional.) i2mo, 2 50 

Keep's Cast Iron 8vo, 2 50 

Kunhardt's Practice of Ore Dressing in Europe 8vo, i 50 

Le Chatelier's High-temperature Measurements. (Boudouard — Burgess.) . i2mo, 3 00 

Metcalf's Steel. A Manual for Steel-users i2mo, 2 00 

Smith's Materials of Machines i2mo, i 00 

Thurston's Materials of Engineering. In Three Parts 8vo, 8 00 

Part II. — Iron and Steel 8vo, 3 50 

Part III. — A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents 8vo, 2 50 

Ulke'sIModern Electrolytic Copper Refining 8vo, 3 00 

MINERALOGY. 

Barringer's Description of Minerals of Commercial Value. Oblong, morocco, 2 50 

Boyd's Resources of Southwest Virginia 8vo, 3 00 

Map of Southwest Virginia Pocket-book form, 2 00 

Brush's Manual of Determinative Mineralogy. (Penfield.) 8vo, 4 00 

Chester's Catalogue of Minerals 8vo, paper, i 00 

Cloth, I 25 

Dictionary of the Names of Minerals 8vo, 3 50 

Dana's System of Mineralogy Large 8vo, half leather, 12 50 

First Appendix to Dana's New "System of Mineralogy.". . . .Large 8vo, i 00 

Text-book of Mineralogy 8vo, 4 00 

Minerals and How to Study Them i2mo, i 50 

Catalogue of American Localities of Minerals Large 8vo, i 00 

Manual of Mineralogy and Petrography i2mo, 2 00 

Egleston's Catalogue of Minerals and Synonyms 8vo, 2 50 

Hussak's The Determination of Rock-forming Minerals. (Smith.) Small 8vo, 2 00 

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* Penfield's Notes on Determinative Mineralogy and Record of Mineral Tests. 

8vo, paper, o 50 
Rosenbusch's Microscopical Physiography of the Rock-making Minerals. 

(Iddings.) 8vo, 5 00 

* Tillman's Text-book of Important Minerals and Docks 8vo, 2 00 

Williams's Manual of Lithology 8vo, 3 00 

MINING. 

Beard's Ventilation of Mines i2mo, 

Boyd's Resources of Southwest Virginia Svo, 

Map of Southwest Virginia Pocket-book form, 

* Drinker's Tunneling, Explosive Compounds, and Rock Drills. 

4to, half morocco, 

Eissler's Modern High Explosives ' Svo, 

Fowler's Sewage Works Analyses i2mo, 

Goodyear 's Coal-mines of the Western Coast of the United States i2mo, 

Ihlseng's Manual of Mining 8vo, 

** Iles's Lead-smelting. (Postage gc. additional.) i2mo, 

Kunhardt's Practice of Ore Dressing in Europe Svo, 

O'DriscoU's Notes on the TreatTient of Gold Ores Svo, 

* Walke's Lectures on Explosives Svo, 

Wilson's Cyanide Processes i2mo, 

Chlorination Process i2mo. 

Hydraulic and Placer Mining i2mo, 

Treatise on Practical and Theoretical^MineJVentilation i2mo, i 25 

SANITARY SCIENCE. 

Copeland's Manual of Bacteriology. (In preparation.) 

Folwell's Sewerage. (Designing, Construction,"'and Maintenance.) Svo, 

Water-supply Engineering . .Svo, 

Fuertes's Water and PubUc Health i2mo, 

Water-filtration Works i2mo," 

Gerhard's Guide to Sanitary House-inspection i6mo, 

Goodrich's Economical Disposal of Town's Refuse Demy Svo, 

Hazen's Filtration of Public Water-supplies Svo, 

Kiersted's Sewage Disposal i2mo. 

Leach's The Inspection and Analysis of Food with Special Reference to State 

Control. {In preparation.) 
Mason's Water-supply. (Considered Principally from a Sanitary Stand- 
point.) 3d Edition, Rewritten 8vo, 

Examination of Water. (Chemical and Bacteriological.) i2mo, 

Merriman's Elements of SanitaryJEngineering Svo, 

Nichols's Water-supply. (Considered Mainly from a Chemical and Sanitary 

Standpoint.) (1S83.) Svo, 

Ogden's Sewer Design i2mo, 

* Price's Handbook on Sanitation i2mo, 

Richards's Cost of Food. A Study in Dietaries i2mo. 

Cost of Living as Modified'by Sanitary'Science i2mo, 

Richards and Woodman's Air, Water, and Food from a Sanitary Stand- 
point Svo, 

* Richards and Williams's The Dietary'Computer Svo, 

Rideal's Sewage and Bacterial Purification of Sewage Svo, 

Turneaure and Russell's PubUc Water-supplies Svo, 

Whipple's Microscopy of Drinking-water Svo, 

Woodhull's Notes and MiUtary Hygiene i6mo, 

15 



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MISCELLANEOUS. 

Barker's Deep-sea Soundings 8vo, 

Emmons's Geological Guide-book of the Rocky Mountain Excursion of the 

International Congress of Geologists , . . .Large 8vo, 

Ferrel's Popular Treatise on the Winds 8vo, 

Haines's American Railway Management i2mo, 

Mott's Composition.'Digestibility.and Nutritive Value of Food. Mounted chart. 

Fallacy of the Present Theory of Sound i6mo, 

Ricketts's History of Rensselaer Polytechnic Institute, 1824-1894. Small 8vo, 

Rotherham's Empnasized New Testament Large 8vo, 

Steel's Treatise on the Diseases of the Dog 8vo, 

Totten's Important Question in Metrology 8vo, 

The World's Columbian Exposition of 1893 4to, 

Worcester and Atkinson. Small Hospitals, Establishment and Maintenance, 
and Suggestions for Hospital Architecture, with Plans for a Small 
Hospital i2mo, i 23 

HEBREW AND CHALDEE TEXT-BOOKS. 

Green's Grammar of the Hebrew Language 8vo, 3 00 

Elementary Hebrew Grammar i2mo, i 2S 

Hebrew Chrestomathy 8vo, 2 00 

Gesenius's Hebrew and Chaldee Lexicon to the Old Testament Scriptures. 

(Tregelles.) Small 4to, half morocco, 5 00 

Letteris's Hebrew Bible 8vo, 2 23 

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